Here are over 1,000 types of cactuses with pictures for cactus identification, separated by their genera.
What Type of Plant is a Cactus?
Cactus belongs to the succulents’ group, plants that can absorb and store large amounts of water in their plant body and roots. In this way they can go without water for extremely long periods. The thorns also have a similar function. They can absorb dew and thus provide extra moisture.
The cactus is from the plant family of the Cactaceae. There are about 300 genera and 3,000 species. The family has many well-known species because they are easy to keep alive as a houseplant and are seen as decorative.
The plants can be classified according to their shapes. There are the disc shape, the spherical shape, and the columnar shape. Certain cactus types can become very large, others remain very small.
There are many other types of succulents in the world, but they lack areoles, places where the thorns (spines) grow. This is characteristic of cacti and family characteristics.
Most cacti are native to North, Central and South America. They occur there in deserts and steppes, on high mountain slopes and in jungles. They are masters of adapting to living conditions. A small number of species occur in tropical rainforests. They then grow as epiphytes on tree branches where, despite the high rainfall, due to the rapid flow of water, dry conditions predominate.
- What Type of Plant is a Cactus?
- [A] Types of Cactuses with Pictures
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1,000 Types of Succulents with Pictures
[A] Types of Cactuses with Pictures
Acanthocalycium is a genus of cactus consisting of several species from Argentina. The taxon name comes from Greek akantha and kalyx, which refers to the spines on the floral tubes. These plants are globose to elongate, with numerous ribs on the spiny stems.
Examples of Acanthocalycium cacti:
Acanthocereus species are primarily sprawling or shrubby plants often with arching stems. These stems are distinctly angled with between 3 and 5 ribs although possibly only 2 or as many as 7 in rare cases and may or may not be segmented. Flowers are white in all species and are nocturnal; and at least some species quite fragrant. Spines are thorn-like, that is short and stout. Flower tubes have spines and scales and the fruits may or may not have spines. Mature fruits are red and globular containing large black seeds in a red pulp.
This genus occurs in the tropics of Southern Mexico, Central America, Northern South America, the Caribbean and even Florida.
Examples of Acanthocereus cacti:
Two species from Coahuila and Nuevo Leon-Mexico make up the entirety of the Genus Acharagma. These plants have globose bodies less than 3 inches in diameter and no more than 3 inches high. They may be somewhat cylindrical in shape and typically grow as individuals, but may put off several offsets from the bottom.
These plants have tubercles and flower from the top, which is similar to both Escobaria and Coryphantha, however, they do not have a groove from the areole to the axis. In fact, the name Acharagma means in Greek “no groove”. [a (no) – charagma (groove)]. The flowers are white to red to yellow and the sepals at least have a darker vertical stripe. The spines are quite thick and can obscure much of the stem and are less than an inch in length. The fruits are smooth little pods that are green to purple colored.
Examples of Acharagma cacti:
Nearly all, if not all, cacti enthusiasts have great admiration for the genus, Ariocarpus. The rugged stone-like appearance and geophytic, subterranean bodies of these plants are not only unique among cacti, but quite unique among plants. In addition, it is well-known that they are very slow growing and so when enthusiasts see a large plant, they can truly appreciate the achievement, whether it was grown in cultivation or in habitat.
That said, plants in habitat appear much different than those in cultivation. In habitat, the star-shaped rosettes are often flat against the ground and may be mostly buried beneath the soil with large taproots underneath. Extreme conditions keep these plants looking almost dead. In cultivation, on the other hand, admiring growers create ideal conditions for these plants and they are often grown into plump little mounds of green tubercles.
Atypical of cacti, Ariocarpus do not have spines (except when they are seedlings). The flowers come out of the center of the plant and most are pinkish-red or white, but can be yellow. Fruits are non-descript and typically are just dried up material surrounding little black seeds. Ariocarpus are denizens of the Chihuahuan desert of Mexico and South Texas.
Examples of Ariocarpus cacti:
This Brazil endemic is made up of species that grow in shrubby masses of thin cylindrical stems branching from the bottom. Stems in one species may reach 3 inches in diameter, but are much thinner in the others and can reach 6 1/2 feet tall. Close-set and bristly spines obscure the plant body which has small ribs underneath.
Flowers come out of the very end of the plant each season creating punctuated growth rings as the stem will continue growing from the tip, leaving a collar of spines at between the new and old segments. The flowers are candy-like waxy tubes of brilliant color -pink, red, white, or yellow and last only one or two days and then turn black and fall off. Fruits are small juicy berries – pink, purple or red.
Examples of Arrojadoa cacti:
The generic name “Astrophytum” derives from the Greek words astron, meaning a “star” and phyton, meaning “plant”. The Genus name implies: “star plant”.
The Astrophytum genus is comprised of 4 species of globose to short cylindrical cacti and one sprawling, octopus-like member. While each species is quite distinct, these four feature a star-shaped appearance when viewed from above. Hence the name Astrophytum, which means star plant. Astrophytum species have been frequently compared to marine life, in particular A. asterias for its striking similarity to sea urchins.
The fifth member of this group was newly discovered in 2001. A. caput-madusae is quite distinct from the other members of the genus and actually very distinct from all other cacti genera as well. Hence, many enthusiasts feel it should be part of its own genus and cosider it to be the sole species in the genus Digitostigma. The name Digitostigma describes the long digit-like tubercles that grow something like an octopus.
Despite the noticeable differences, all 5 species including caput-madusae feature a sort of flocking of white trichomes (or bumps) on the epidermis. Although in cultivation some forms are bred for their lack of flocking. Plants in this genus also all have yellow flowers with fuzzy floral tubes. Some have a red-centered flower, all are radially symmetric and eventually turn into dry, fuzzy seed pods bearing relatiely large, black seeds that are among the easiest to germinate.
The four original Astrophytum members have been extremely popular in cultivation and numerous exotic hybrids have been created that accentuate various features such as amount of flocking, number of ribs, lack of spines, etc. With the uniqueness of caput-madusae coupled with its late discovery, it is currently one of the most sought-after cactus species by collectors world-wide. And in that sense, it is fits in quite well with the other Astrophytum species.
Astrophytum is a Chihuahuan desert native occurring in north/central Mexico and southern Texas, USA.
Examples of Astrophytum cacti:
Austrocactus is a genus of cacti with ten species endemic to southern South America, in Argentina and Chile.
They have solitary or branched bodies; the ribs are usually divided into tubercules (except Austrocactus spiniflorus). The tallest species in this genus is 80 centimeters. Flowers are pink, orange, red or yellow with a characteristic spiny tube.
Examples of Austrocactus cacti:
The prefix Austro means southern and so this is the South American version of Cylindropuntia. However, there are differences beyond geography that separate this shrubby group of cacti into their own genus. Clearly members of the opuntiads, this genus features round succulent leaves on new growth that fall off with age and the opuntia trademark glochids within the areoles.
New stems and flower buds arise from areoles along existing stems, but Austrocylindropuntia differs from Cylindropuntia in that the spines lack papery sheaths. The stems also grow without distinct segments between growth points. Flowers are yellow, orange, or red on stout spiny floral tubes. Fruits are thick and rounded.
Two of the eleven species are especially popular in cultivation; A. subulata and A. cylindracea are extremely hardy, fast growing, and make formidable landscape plants in warmer climates.
Examples of Austrocylindropuntia cacti:
Two species make up the genus Aztekium that were discovered over 60 years apart. Despite this gap in discovery, the two species clearly belong in the same genus. Both grow on vertical or near-vertical gypsum cliffs where little else will grow. They grow in the Mexican state of Nuevo Leon in separate populations; each in a single valley. With such limited distribution, these extreme survivors need serious protection to keep from becoming extinct in the wild due to illegal collecting.
Both species are star shaped. A. ritteri which was discovered first, has rounded ribs with many transverse wrinkles making even young plants look ancient. A. hintonii on the other hand has much more acute or distinct ribs with more uniform cross banding on the ribs. Spines are not prominent on either species. Both species are fairly small, with stems not exceeding 4 inches in diameter and typically are half that size. A. hintonii stays solitary, while A. ritteri tends to form clumps when older.
Flowers are dainty and loose, arising from the apex of the plant. Hintonii has dark pink flowers and ritteri has white flowers with a faint pink stripe.
Because of the limited distribution and the unusual growth habits of this genus, it is much sought after by experienced cacti enthusiasts. However, it is especially slow-growing and not especially easy to grow. As a result, most plants in cultivation are grafted specimens that survive on a much hardier root stock.
Examples of Aztekium cacti:
[B] Types of Cactuses with Pictures
Bergerocactus emoryi (golden cereus, golden-spined cereus, golden snake cactus) is a species of cactus. It is the sole member of the genus Bergerocactus, named after Alwin Berger. The plant is also known as snake cactus, though this latter name also applies to Echinocereus pensilis.
Example of Bergerocactus cactus:
Small in stature, but big in interest, Blossfeldia is a single-species genus that is the smallest of all cacti maxing out at 1/2 inch (12mm) in diameter. The species name of liliputana attests to its small stature as it is derived from the island Lilliput from the novel Gulliver's Travels where all the people where tiny. These plants may grow as solitary little buttons or form many-stemmed clumps. They do not have ribs, tubercles, or spines. Flowers are white, delicate, and may slightly exceed the diameter of the entire stem.
Blossfeldia grows on the eastern side of the Andes mountains in Bolivia and Argentina from 4,000 to almost 12,000 feet in elevation. In this harsh environment, this remarkable species can survive extreme drying out.
Examples of Blossfeldia cacti:
The genus takes its name from the Greek brachys, meaning short, which refers to the plants fairly low-growing stature.
Most people think of wild reptiles or birds when they think of the Galapagos Islands, but this archepellago of unique fauna and flora also boasts some very unusual cacti. Brachycereus nesioticus is one of those. The monotypic genus features a cactus that seems able to grow in seemingly impossible conditions.
Brachycereus forms clusters of stems on exposed lava flows on several of the islands where virtually nothing else grows. The stems are cylindrical and grow to around 2 feet (60cm) in height. Spines are yellow to brown and cover the stem. Flowers are white and form on the end of a long narrow floral tube of just over 4 inches (11 cm).
This genus is virtually unknown in cultivation due in part to the difficulty of obtaining seeds or cuttings as everything on the Galapagos is strictly protected. It is also reportedly a difficult species to grow.
Examples of Brachycereus cacti:
Brasiliopuntia is a genus in the cactus family, Cactaceae. It contains only one species, Brasiliopuntia brasiliensis. It is found in Brazil, Paraguay, eastern Bolivia, Peru and northern Argentina, and has become naturalized in Florida among other places.
Examples of Brasiliopuntia cacti:
Plants are treelike columnar cacti up to 33 (10m) feet in height. Most species have many shallow ribs which may be tuberculate. Spines are notable in many species in that young growth is heavily spined while older growth has few spines. Flowers are white or red and have large scales on the floral tubes. Fruits are small. These species hail from Bolivia, Chile, and Peru and are seldom grown in cultivation.
Examples of Browningia cacti:
[C] Types of Cactuses with Pictures
Carnegiea gigantea (Saguaro cactus), the single species in this monotypic genus, is certainly the most widely recognized and stereotypical cactus of all. The large Saguaro is a symbol of the desert Southwest and has symbolized the west in general in cartoons, on post cards, book covers, paintings, sculptures, etc. Because of this, many people associate the large, branched cacti with the west, however, in reality these quintessential cacti occur in the U.S. only in central/southern Arizona and a tiny bit into California on the Arizona border.This is quite the opposite of the widespread occurrence many people romantically incorporate with their impression of the Wild West.
Nonetheless, anyone who has stood beneath these magnificent giants can easily see the reason for their popularity. Cacti are foreign enough to the majority of the world with their leafless, succulent, spiny bodies; but add to that heights in excess of 50 feet and monstrous branches and the result is quite awe-inspiring and more than enough to fuel endless folklore and tall tales.
Examples of Carnegiea cacti:
Cephalocereus is not an especially fast-growing genus and the plants are large columnar species up to nearly 50 feet (15m). Despite this, at least one of the species, C. senilis is especially popular in cultivation because of the very distinct long white hair that makes smaller plants look like “Cousin It” from The Adams Family. The other species are almost unknown in cultivation and still have wool or hair, but not nearly as prominent as C. senilis. Flowers are produced in lateral cephalium, hence the name. All 6 species currently recognized in this genus grow in southern Mexico.
Examples of Cephalocereus cacti:
Earlier in cactus taxonomy, Cereus is a name that has been applied to nearly all known cactus species that were ribbed, columnar plants. Many of these plants have since been moved out into separate genera. Consequently, the 30 or so plants that remain in the Cereus group are largely plants that have not been moved out of the genus rather than plants that have been included because they fit the description of Cereus. This inclusion-by-lack-of-exclusion makes for a very messy and unsatisfactory grouping.
The stereotypic Cereus is a large, tree-like columnar plant with 4 to 10 well-defined ribs, large areoles, and moderate, stout spines. The flowers are large and white with floral tubes that are smooth or have smooth scales; they are nocturnal and fragrant. Some of the species that fit nicely into this description are C. hexagonus, C. hildmannianus, C. jamacaru, C. lanosus, and C. repandus among others. Exceptions to this are the sprawling, thin, climbing species like C. albicaulis, C. spegazzinii, and C. kroenleinii. A shrubby, thin-stemmed species, C. insularis resembles the Genus Cleistocactus while C. mortensenii bears a pseudocephalium.
Examples of Cereus cacti:
11 Cereus Cactus Types & Care
Cintia knizei is a small alpine cactus native to the high Andes of Bolivia. The plant was discovered by Karel Kníže in 1969 at an elevation of 4,000 m (13,000 ft) near Otavi, in Potosí Department, Bolivia. However, it was not formally described until 1996 by Jan Říha.
Examples of Cintia cacti:
Cipocereus is a small group of Brazilian short columnar species most notable for the blue-colored fruits of most species. This fruit has a watery pulp and this trait has been a key factor in placing species within the genus. This genus dates to 1979 although some of the species were known under different genera for many years before that. Once the genus was created by F. Ritter, he and other taxonomists moved in a few species from elsewhere and one new species was discovered not previously named.
Examples of Cipocereus cacti:
From the Greek Cleistos, meaning closed. As in the genus Cleistocactus whose flowers seldom fully open.
Some might say that Cliestocactus is a genus of quantity over quality. That is, many of the features of this genus are small, but profuse. The stems are typically only an inch or so in diameter, but branch readily at the base to form noticeable clumps. The spines in general are likewise small and flexible, but in most cases are very numerous even to the point of obscuring the stems. This trait is continued with the flowers. Many species have flowers that resemble little tubes of lipstick or firecrackers. Yet the stems may be full of these flowers with many buds in the making. In the right conditions a plant may have flowers open every day of the year.
This genus is widespread throughout much of South America and can be found growing in large shrubby clumps mixed in with other vegetation or clamoring over boulders. Several species are extremely popular in cultivation and are among the most common of cactus in nurseries worldwide; the two most popular of all being C. strausii and C. winteri.
Examples of Cleistocactus cacti:
Coleocephalocereus is a genus of erect and semi-erect columnar cacti from Brazil. These species develop a cephalium with wool and bristles. They are common to the inselbergs of the Brazilian Atlantic rainforest, and can comprise a dominant portion of the flora in these isolated, dome-shaped rocky outcrops.
All species are short columnar plants while a subspecies of C. aureus remains more globose. The stems feature multiple shallow ribs up to 35 in number that may be somewhat tuberculate, but are more often straight. Moderate spination comes out of small, closely spaced areoles. The most distinctive feature of the genus is the lateral cephalium out of which come small tubular white or red flowers. Fruits are small rounded and reddish colored.
The genus is unusual in cultivation, but not unknown with the smaller, more manageable C. aureus and C. purpureus being considerably more common than the other species.
Examples of Coleocephalocereus cacti:
Consolea is a group of Opuntiads from the Caribbean (including Florida, U.S.). They are all small-tree-like plants (20 feet tall at most) that start out as flat pads called cladodes, which later develop into round trunks. At the end of these trunks, new cladodes give the appearance of leaves messily arranged about the top. This feature of straight, round, unsegmented stems are unique to Consolea and this helps define the genus.
In addition, the flowers bear parts that are unique among other Opuntiads, specifically the seeds, pollen and floral nectary. The flowers themselves are small, mostly under 1inch in diameter and rise out of pericarpels which are comparatively large and may or may not have spines.
As with many other Opuntiads, some Consolea species are quite common in collections or nurseries, but receive little attention. Often, they are simply labeled “Opuntia”. They are quite vigorous growers which accounts in part for their popularity along with some species lack of any threatening spines and/or glochids.
Examples of Consolea cacti:
Copiapoa is a favorite genus among many cactus growers. While not known for any particular characteristic, such as the large flowers of Echinopsis, the species in Copiapoa exhibit a wide degree of “variation on a theme”. In common with each other, Copiapoa species are globose or globose-cylindrical plants that have well-defined ribs and a wooly apex which gives rise to nearly all yellow flowers. These flowers are funnel shaped, mostly between 1 and 2 inches in diameter, and are quite similar from one plant to the next.
In contrast, the spines may be long and fierce or mostly absent. The roots may be fibrous or huge tubers that are larger than the portions above ground. Some plants are small individuals many form clumps, some imposing mounds of several feet across with hundreds of stems. Coloration is also a variable even with in the same species from glaucous blue-green, to deep green to brown. In this way, it is easy to identify a given plant as one belonging in the genus Copiapoa, but it is conversely difficult to then decide to which species it belongs.
As previously stated, Copiapoa is widely popular in cultivation. In the wild the genus is restricted to Northern Chile. There they are found primarily in the Atacama Desert where annual rainfall is barely measurable. The plants in habitat get their moisture from coastal fogs. Images from this habitat often reveal vast barren areas where Copiapoa plants or clumps march across the void along with almost no other vegetation.
Despite the extreme and specific conditions in habitat, Copiapoa as a whole are surprisingly easy in cultivation. From seed sewing to the care of mature plants, this genus is very forgiving. While staying manageable in size, Copiapoa in cultivation will flower from a young age and reliably so each following year.
Examples of Copiapoa cacti:
Coryphantha, or beehive cactus, is a genus that consists of relatively small, globose plants that have grooved tubercles instead of ribs. Other genera are similar to Coryphantha including Mammillaria and Escobaria. In fact, most Coryphantha where at one time included in the genus Mammillaria, but they differ primarily in that Coryphantha flower from the first-year growth at the apex of the plant while Mammillaria do not flower from new growth and instead flower in rings further down the plant in mostly second-year growth.
Escobaria on the other hand flower from the apex as do Coryphantha and nearly all Escobaria were once included in the genus Coryphantha in past cactus taxonomy. The difference between these two is more subtle in that Coryphantha seed coats (testa) are reticulate. In other words, with a net-like or crisscrossing pattern whereas Escobaria seed coats are foveolate, meaning pitted.
Geographically, Coryphantha occur in the arid regions of the Southen U.S. and Northern Mexico while Mammillaria occurs from this range to the south and Escobaria from this same area to the north. This comparative distribution being the general state, not the range without exception. Aside from the distribution of these plants, Coryphantha typically have larger, mostly yellow flowers compared with smaller more often pink flowers of the other related genera. Again, this is not without exception.
In cultivation, this genus is not at all rare, but often plants exist without adequate identification. This is especially problematic because Coryphantha plants are quite variable from seedling to mature age plants. Likewise, the presence of a central spine and/or extrafloral nectaries is variable even in mature plants. In this way several plants of the same species may appear quite different based on their age or expressed traits.
Examples of Coryphantha cacti:
As more and more work is done on the Opuntiads, more species are broken out of the genus Opuntia and placed into separate genera. Cumulopuntia is one of the earlier groups to be recognized as distinct from the genus Opuntia, however, many were placed into the even earlier genus of Tephrocactus primarily by Backeberg in the 1950’s. Then in 1980, F. Ritter created the new genus Cumulopuntia taking species from both Tephrocactus and Opuntia. The primary distinction was in the fruits which contain no pulp. Seed structure is also unlike other Opuntiads and overall growth is that of a compact cushion.
At least 30 or more species have been described for the genus, but this was reduced by Anderson (who followed James Iliff) to just 20 species and in The New Cactus Lexicon the genus was dramatically reduced to just 4 species, one having 4 subspecies for a total of 7 taxa.
These plants are found often at high elevation in south-central South America. In cultivation, plants are only found through specialist nurseries or traded between growers. This is not unlike other Opuntiads which are often hated or loved by cactus growers with the former being more often the case.
Examples of Cumulopuntia cacti:
Collectively known in the vernacular as “Cholla”, the species of the genus Cylindropuntia are rarely grown except by die-hard Opuntia-lovers. Despite their absence in cultivation, Chollas are quite well known. This is one of the most prolific and prominent cactus genera of the deserts of the Southwest United States and Northern Mexico. As a whole, Cylindropuntia consists of segmented cylindrical stems which grow in the form of small trees rarely exceeding 10 feet in height.
Most of the species have tuberculate stems that are heavily armed with spines. The spines of this genus are covered in a papery sheath, which may fall of in time. This sheath gives some species a silvery or gold appearance. It makes plants appear to glow in the morning or evening when the sun is low and the plant is between sun and observer.
The spines are also quite fiercely reverse-barbed which makes them grab firmly to the skin of unwitting passers-by and are consequently very painful to remove. Likewise, some species have stem-segments which detach easily and this combination of characteristics has earned several the common name of “Jumping Cholla”. This being because the grab and detach trait is so surprising, one is under the impression the cactus jumped to grab hold of the victim. In this manner, species of Cylindropuntia can be spread and propagated by passing animals as any of the stem segments will grow into a new plant.
Flowers are cup-shaped, waxy, and often yellow however, they may be red, orange, or even translucent green. Some species may have multiple flower colors from plant to plant. The fruits of Cylindropuntia are especially useful in identification based on color, spines, overall shape, etc. Cylindropuntia are also among the most drought and heat tolerant of any species. Their dense spine cover and thin stems making them well equipped to fend off the powerful desert sun. In the harsher areas of the North American deserts, a Cholla may be the only cactus present where only creosote bush (Larrea tridentada) grows as its companion.
Examples of Cylindropuntia cacti:
[D] Types of Cactuses with Pictures
The genus Discocactus is highly prized by collectors around the globe. Exactly what it is that makes them so attractive is uncertain. Some of the factors are likely their relatively compact size, unique and showy white flowers, and their slow growth. The species within this genus are flattened to globose in shape with stems that hardly exceed 3 inches (7.5cm) in height and are less than 10 inches (26 cm) in diameter. Stems are ribbed and sometimes tuberculate with fuzzy areoles or dense spines.
Most plants remain single, but may form clumps. Flowering plants form a wooly terminal cephalium out of which rise the white flowers on the end of a long, thin floral tube. The nocturnal flowers are highly fragrant and touted by many growers as the best smelling of all cactus flowers.
Discocactus plants in the wild hail from Eastern South America and all are listed under CITES I due to habitat loss. In cultivation, plants are frequently grafted to speed seedling growth. A large number of names have been given especially for some species that are still used by hobbyists, but reduced to synonymy by many taxonomists.
Examples of Discocactus cacti:
Disocactus is a genus consisting of mainly epiphytic, though sometimes lithophytic, species that grow in tropical jungles rather than deserts. With the majority of species occurring in Central America and Southern Mexico, however some extend into northern South America and even onto the Caribbean islands. There is a good deal of variation in both the stems and flowers of species included in this genus, leaving the taxonomy of Disocactus contested by many. Other genus name that are frequently used today for certain species included here by default are Ackermannia, Nopalxochia, and Wittia.
Stems may be long, flattened and leaf-like – very closely resembling those in the genus Epiphyllum. Others have cylindrical and spiny stems. Flowers for the most part are large, colorful, and funnel shaped and this genus is largely responsible for many of the popular “Epi” hybrids. Other flowers are more narrow and bilaterally symmetrical and some are even small and tube shaped.
Certain species of Disocactus have persisted cultivation for over 100 years and have been passed down by “aunts and grandmothers” for generations. This is especially true with D. ackermannii and D. phyllanthoides, however, some of them may be very early hybrids and not the actual species.
Examples of Disocactus cacti:
[E] Types of Cactuses with Pictures
The seemingly small genus of Echinocactus is widely accepted lately to include 6 species. Historically, the name Echinocactus has included many hundreds of species. This is a result of early cactus taxonomy in which a few names were used to cover large groups of cacti with an overall similarity with each other. In the case of Echinocactus any plants that were barrel shaped, ribbed, and not already included in Cereus or Melocactus found inclusion in the genus Echinocactus.
The famous cactus taxonomists, Nathaniel Britton and Joseph Rose then moved most species into separate genera during the early 1900’s. There are some cactus enthusiasts who find themselves uncomfortable with the grouping of the remaining six species. They consider it largely a genus of convenience as there are differences between these six species that in other groups are used to define separate genera for otherwise similar species.
That being said, the remaining six species in Echinocactus do have several traits in common. Most significantly, they develop a dense, fuzzy wool at the apex which gives rise to the flowers in mature plants. This can be a wide, flat area covering almost the whole top of the plant in E. grusonii and E. platyacanthus or very limited and hardly noticeable as in E. texensis.
Other similarities in this genus are an overall barrel shape and well-defined ribs. All species have robust spines and produce yellow or pink funnel shaped flowers. These later characteristics make Echinocactus appear very similar to the larger genus, Ferocactus aside from the wooly apex. Echinocactus fruits may be dry and wooly or fleshy and round.
While the many species that were previously included in Echinocactus ranged all over North and South America, the 6 remaining species are indigenous to the Southwestern United States and Mexico. In cultivation, the species E. grusonii – commonly referred to as the “Golden Barrel” – is easily one of the most popular of all cactus species grown.
It is very easy to propagate from seed, grows fairly quickly, is tolerant of a range of treatment or mistreatment and has a striking appearance due to its golden-yellow spines. Ironically, it is nearly extinct in the wild and exists in only a very small area geographically. Conversely, the other species, are much more wide-spread, but are much less prevalent in cultivation. E. polycephalus is notoriously difficult to grow in cultivation due in part to its slow growth and affinity for high temps and low humidity.
Examples of Echinocactus cacti:
Echinocereus is a genus that is much loved by cactus growers world-wide. There are several characteristics that collectively account for their popularity. All Echinocereus are small plants that are quite suitable for growing in pots and greenhouses. The stems of this genus are more often than not under a foot in height and perhaps 2 or 3 inches in diameter. Some are slightly bigger, some smaller. In the wild, some species may form large mounds of many hundreds of stems, but this takes many years and these same species are still quite manageable in cultivation.
There is a wide variety of spination that includes some of the most fierce and dramatic spines covering the plant stem so that it is not even visible. Most have moderately sized spines evenly distributed; some have very colorful spines even in alternating patterns. Some have pectinate (comb-like) spines and some are nearly spineless. The spines are arranged on ribs.
Aside from being a cultivation-friendly size, Echinocereus have some of the most brilliant flowers of the cactus family. They range in color from electric-pink to deep scarlet to translucent browns and greens and even bright yellow. Many species feature two-toned flowers with one color toward the center and another color on the outer parts of the flower.
One particular population exists in New Mexico, USA of naturally occurring hybrids that display much of this color range on one hillside from plant to plant. The flowers can be 3 inches or more in diameter and feature spiny floral tubes. Close examination reveals that the flowers actually break through the epidermis of the stem as do any new offsetting stems.
In the wild, Echinocereus range from as far north as South Dakota, USA and south through most of Mexico. They inhabit a wide range of habitats growing under Ponderosa forests to coastal plains; from low elevation deserts to mountainsides of 8000 feet or more. There can be a tremendous amount of variation within species and this can make identification especially tricky in some instances.
Examples of Echinocereus cacti:
Another denizen of the Southwestern United States and nearby Mexico is the genus Echinomastus. This is a relatively small group of cacti (5-9 species, according to Powell and Weedin, 2004) that are short, elongated globular plants. The stems seldom branch and for the most part do not exceed 12 inches in height. The stems are typically very heavily spined to the point of obscuring the stems. The spines rise from areoles on distinct tubercles arranged in rows. There exists a groove on the tubercles and extrafloral nectaries are sometimes present.
Flowers are red, pink, cream-colored or even brownish and funnel shaped. The diurnal flowers, originating from the tips of the tubercles, come from the apex of the plant often fighting their way through a tangle of spines. The fruits dehisce either at the bottom or longitudinally when ripe.
The status of the genus Echinomastus is uncertain. In The New Cactus Lexicon (2006), the genus has been eliminated and all species placed under Sclerocactus. In The Cactus Family (2001), Anderson retains Echinomastus because of Porter's research (1999) showing distinct molecular differences from Sclerocactus.
Examples of Echinomastus cacti:
The only cactus genus that is more confusing than Echinopsis is that of Opuntia. In both cases, there is a great number of species (over 100) and a tremendous amount of variation. In Echinopsis plants range from very small, flattened-globose plants to quite large, treelike giants. As a result, there is a long list of synonymous names for many of the species. Some synonyms referring to other synonyms that refer to a subspecies of some seemingly distinct species. Sorting through these names often feels like a wild goose chase and is quite frustrating.
In more recent thinking, the previous two genera of Trichocereus and Lobivia are included with Echinopsis. However, it is not at all uncommon for enthusiasts to use all three names in discussion even if their labels read Echinopsis. This usage reflects the general (inexact) situation that the larger, columnar members are distinguished as Trichocereus while Lobivia includes a select group of smaller, not-as-spiny plants which typically flower from low on the plant similar to most Rebutia species. This leaves the bulk of plants referred to as Echinopsis to be mostly spiny, ribbed, globose plants.
The main factor that ties these plants together are their very large, showy flowers. These flowers are all very similar in structure – funnel shaped, with hairy/wooly scaled floral tubes which give rise to hairy, globular fruit filled with a soft, mushy pulp. The flowers seldom last more than a single day and may be diurnal or nocturnal depending on the species. These species hybridize easily and have resulted in a tremendous number of hybrids that some cactus growers specialize in or grow exclusively. There are certainly enough hybrids to keep even ardent hobbyists busy.
Because of their exceptional flowers, many Echinopsis species are found in garden centers and collections world-wide. The larger species (aka Trichocereus) are also popular landscape plants in warmer parts of the world. While there are a number of species common in cultivation, there are as many or more unknown hybrids in the trade. These hybrids are easy-to-grow and produce nice flowers, but buyer beware if exact names are desired. Plants of this genus are widespread throughout South America and inhabit a wide range of habitats and climates.
Examples of Echinopsis cacti:
Epiphyllum is a genus of 19 species of epiphytic plants in the cactus family, native to Central America. Common names for these species include climbing cacti, orchid cacti and leaf cacti, though the latter also refers to the genus Pereskia.
Examples of Epiphyllum cacti:
Epithelantha is a genus of just two species of small plants. There exists a good deal of variation in spination and consequently more species have been described, most have settled on just the two and described the variations as subspecies. For the most part, this seems to satisfy the taxonomist and hobbyist alike. The plants of both are quite small with stems barely exceeding 2 inches (5cm) in diameter and less-so in height. Whether long or short, the spines are white and grow out of tubercles much like Mammillaria.
However, the flowers rise from new growth out of the spine-producing areoles at the end of the tubercle. This feature clearly differentiates Epithelantha from Mammillaria. The flowers themselves are small, light pink or white funnels that appear very delicate. While these small flowers may go almost unnoticed, the fruit of Epithelantha are quite dramatic. These fruits are long tubes that stick up like birthday candles and their bright red color stands in high contrast to the white spines.
Examples of Epithelantha cacti:
Eriosyce is a group of mostly globose or somewhat cylindrical South American species. Their round ribbed stems, which in most species are heavily armed with dense strong spines, and similar flower structure had earned them a place in the genus Echinocactus in early taxonomies. However, the genus has existed since Rudolph Philippi in 1872 and everyone for the last 100 years or more agrees these plants are not Echinocactus.
Despite this, the default listing here of Eriosyce includes species that are considered unique even today. The two primary names still used today are Neoporteria and Neochilenia with a third name of Islaya being used as a monotypic genus of one species. All three of these names are still commonly found on tags in cactus grower’s collections as well as in the cactus nursery trade.
Many species have been given both the name Neochilenia and Neoporteria at some time in the past. However, modern growers distinguish them in this way: Neochilenia have short to no spines and funnel shaped flowers that enable the inner part of the flower to be clearly seen when fully open. The floral tubes of Neochilenia are hairy and these later form hollow, fleshy fruits. In contrast, species in the Neoporteria group have denser, longer spines in general than Neochilenia.
The flowers are bright pink with yellow interiors and are more of a tube shape as the inner petals remain mostly closed. The outer petals flare out and thus, the flower is not truly a tube shape as other cactus genera, but even when fully open, the inner parts of the flowers are still obscured by petals. The floral tubes may have a little fuzz and form similar fruits to the Neochilenia group. The plants considered Islaya are highly variable and cover a large range in Chile and Peru.
In total, plants in the genus Eriosyce are rugged survivors of arid South American deserts. Many occur at high altitudes where they endure big temperature swings and high UV. To deal with the harsh climate, the plants will sit dormant until conditions are again favorable. This environmentally controlled growth leads to a big discrepancy between plants in habitat and those in cultivation even of the same species.
Plants in cultivations with sparse spines and plump round stems may be flattened and covered with spines so dense that the stem is not visible at all. This variation, as well as the differences described above, has led to an enormous number of synonymous names being published.
Examples of Eriosyce cacti:
The genus Escobaria includes species of small globose to cylindrical solitary or clumping stems with tubercles. Many of the species were once included in Coryphantha and earlier in Mammillaria. The inclusion in Mammillaria was largely due to overall habit of the plants and especially the presence of tubercles. Escobaria differs from Mammillaria in that it flowers from new growth at the top and lacks dimorphic areoles – that is the areoles do not have separate parts for producing spines and areoles.
The distinction from Coryphantha is more subtle and is primarily in the seeds. The seeds of Escobaria are pitted (foveolate) unlike the crisscrossed (reticulate) seeds of Coryphantha. While the seeds are necessary to make a consistent distinction, other more generalized guidelines help differentiate Escobaria from Coryphantha. These other features include: a lack of extrafloral nectaries, fringed edges on the flowers, corking and falling off of tubercles with age and smaller, typically pink flowers.
Escobaria have a grooved tubercle and some otherwise similar plants have been moved out of Escobaria and into a separate genus Acharagma for lacking this groove.
Several species of Escobaria are quite popular in cultivation, but most notable are the species which are cold hardy. While many species are from warmer Mexico and the Southern United States, two species in particular range all the way north into Canada. It is these northern plains species that gardeners delight to grow in their cold-hardy gardens to break up the monotony of otherwise Opuntia-filled beds. There is also a species on the island of Cuba.
Examples of Escobaria cacti:
The genus Espostoa consists of a dozen or so species from Ecuador, Peru, and Bolivia. They are columnar plants that mostly branch at the base to form a series of stems reminiscent of a big city skyline. The most notable feature of Espostoa is presence in most species of dense, white “hair” which quite dramatically covers the stems giving them a soft, fuzzy appearance. This is just an illusion however, as underneath the soft hairs are numerous sharp spines arranged on many small ribs which circle the columns. In some species the main central spine extends well past the hair making their threatening presence obvious.
Several species of Espostoa, are especially popular in cultivation due to their fuzzy white hairy appearance. The plants are typically sold by large commercial growers as 6-12-inch stems. However, being large columnar species, these plants do not grow nearly as vigorously in pots as they would in the ground. Plants tend to quickly fill the pots becoming pot bound and then growth slows to a crawl. As such, these plants rarely, if ever reach maturity meaning they don’t produce the cephalium and subsequently do not flower.
On the other hand, those in warmer climates that can plant the species directly in the ground may indeed have plants that form a nice grouping of stems that will eventually flower.
Examples of Espostoa cacti:
As the name implies, Espostoopsis is very similar to the genus Espostoa. Aside from being disjunct geographically with the single species in Espostoopsis being native to Brazil as opposed to western South America, the differences are not readily apparent. Interestingly, further investigation revealed that taxonomists have never placed this species in Espostoa despite their strong similarities. This is not because it was always a stand-alone species either as it was listed in both Austrocephalocereus and Coleocephalocereus before getting a name of its own in 1968.
Unlike Espostoa, Espostoopsis flower tubes are naked, hence the comparison with Coleocephalocereus and Micranthocereus. Fruits and seeds are less conclusive, partly because they are so variable within Espostoa. Some species have smooth shiny seeds and some rougher, even tuberculate, seed. Espostoopsis has dark tuberculate seed. Some obvious differences arise in the fruit stem as a result of the flower differences.
In any case, the singular species in the genus is a low-branching columnar with many ribs. It has a wooly appearance due to the wooly white hairs that obscure the stems and give rise to central spines which extend well past the hairy covering. White, bell-shaped flowers form out of a lateral cephalium.
Espostoopsis is known in cultivation, but seldom reaches maturity in pots and is grown more as a novelty for its hairy appearance.
Examples of Espostoopsis cacti:
One must know a little about the habitat of the genus, Eulychnia to truly appreciate it. These relatively large plants which reach up to 23 feet (7m) high grow in the deserts along the coasts of Chile and Peru. These deserts receive little to no rainfall and the plants that live there survive from the condensation brought about by the heavy and frequent fog of the area. Here Eulychnia species grow as large shrubs or trees with many branches.
The stems are covered with many long spines arranged on tuberculate ribs. The floral tubes are covered in spines, wool, scales, or all three and are round in shape and when the flower opens, resemble a ball that popped open on one side.
Eulychnia is not common in cultivation and only collectors with a specific interest in the genus seem to grow them.
Examples of Eulychnia cacti:
[F] Types of Cactuses with Pictures
Ferocactus is a genus that has long been a major stereotype for the entire cactus family. Their imposing “barrel” shape can be seen in paintings and other forms of desert art, cartoons, and movies. Bolstered by errant folklore, the Ferocactus has been nicknamed “The Traveler's Friend”. This is due to the belief that these “living barrels” are reservoirs of fresh drinking water in the hot arid deserts just waiting to be tapped into by a parched and wayward visitor.
While this idea is quite romantic and plays well to the imagination, in reality, it is not recommended to drink this water as it is far too alkaline and may worsen the effects of dehydration. A far better source of water can be found in the flattened leaf-like pads of the nearby Opuntia species.
As a whole the species included in Ferocactus are indeed barrel-shaped, but some remain as smaller round stems and some may form clumps of few to many stems. These stems are ribbed and mostly straight, sometimes tuberculate. All species have stout spines, some of them especially thick and heavy and may be hooked or straight. Spines come in a wide range of colors, often varying within species, and may be yellow, gray, white, brown, pinkish, or most notably, brilliant red. On many species, the central spines feature ridges that run perpendicular to the spine.
Flowers come from the top of the plant, often forming a ring around the apex. Flowers vary from yellow to red and are funnel shaped opening from between 1 and 2 inches in diameter. It is not unusual for developing buds to have to fight their way up through seemingly impenetrable masses of spines. The buds are scaly and naked.
Fruits in most species are elongated and bright yellow and retain the dried flower parts at the top. This gives them an uncanny resemblance to little pineapples. As the flowers form in rings around the top of the stem, so the fruits form bright yellow rings and are quite showy. The fruits are mostly dry with a very tough, fleshy skin and contain many hard black or brown seeds.
Examples of Ferocactus cacti:
Frailea species are all small solitary or clustering plants with flattened globose stems that rarely exceed 2 inches (5cm) in diameter. The stems have few to many very shallow ribs which may be straight or wavy. Spines are quite small and weak if present at all and pose little threat to the finger tips. The yellow flowers are often larger than the stems and open in the heat of the day for a short time, if at all.
Frailea species are cleistogamous, meaning that often times the flowers do not even emerge, but rather they self-pollinate while still inside the plant. Many growers new to the genus are often surprised to find a fruit spilling seed all over on a plant that they never noticed in flower. The fresh seed germinates quite easily and because of the surprise fruit that shows up, seeds are already growing at the base of the main plant before the owner knows the seed is there.
Examples of Frailea cacti:
[G] Types of Cactuses with Pictures
Geohintonia is a genus of just a single species. It is a very distinct in appearance – quite unlike any other cacti. The body of these plants are globose to somewhat columnar when older. The have around 20 very prominent ribs with flat sides that looking almost like cooling fins on a circular radiator. The body color of the plants is a frosty, blue-grey. The edges of the ribs are dotted with white areole bearing flexible short spines at the top of the plant and scars where areoles later fall off further down the ribs. Flowers come from the wooly apex and are dark pink, funnelform with yellow stamens and a white stigma.
Examples of Geohintonia cacti:
In The New Cactus Lexicon, all species that are included by default here in Grusonia have been moved into the genus Corynopuntia with the exception of G. bradtiana. Thus, a more recent treatment makes Grusonia a monotypic genus. Clearly a member of the subfamily Opuntioideae, due to the presence of glochids, segmented or jointed stems and the ephemeral leaves which show up on new growth.
Members of the genus Grusonia all-inclusive are mostly low-growing mats of stems with heavy spines on low ribs or slight tubercles. Unlike the similar Cylindropuntia, the spines are not covered with a papery sheath, though some have a little of this trait. Flowers range in color from pink to yellow, even white and are cup-shaped appearing waxy or satin-like. Fruits are typically spiny, fleshy, and dry.
Examples of Grusonia cacti:
It is fairly easy to place an unknown cactus into the genus Gymnocalycium especially with a flower bud. Choosing the species is another matter. The majority of species in this genus consist of globose, solitary plants with ribs that are often only somewhat tuberculate. This slight punctuation along the ribs results in a “chin-like” appearance and this characteristic has earned it the nick-name “Chin Cactus”. In general, each areole has a handful of proportionately-sized spines. Of course, there are exceptions of clumping, strongly tuberculate, or heavily-spined species, but in these cases flower buds will ensure that even these plants belong in Gymnocalycium.
These flowers are defined as being “naked”, that is, without any spines, wool, or bristles. In all species, they are smooth and scaled. Someone resembling the tip of young asparagus shoots. Nearly all species have white, cream-colored or pale-pink flowers, while a few have dark red or yellow. Flower size is moderate among cacti and typically flowers are 1 to 1.5 inches (2.5 to 3cm) wide. While flowers come easy and at an early age on Gymnocalycium plants, they usually need high-heat to open fully and thus do much better in a greenhouse for those outside Arizona!
The largest of this genus may attain to around 7 inches (16cm) high and 12 inches (30cm) in diameter, while most species stay well under 5 inches (13cm) in height and diameter. This small size and relatively easy-care requirements make this genus very popular in cultivation.
Among the most popular is the red-flowered, G. baldianum and the unusually colored G. mihanovichii. The latter of these is even more popular as a grafted mutation of either variegated or chlorophyll-lacking, bright red plants incapable of surviving on their own roots. In fact, these might be one of the most prolific plants in cultivation as they are sold in large retail outlets as a novelty with the name “Lollipop Cactus”.
Examples of Gymnocalycium cacti:
[H] Types of Cactuses with Pictures
Haageocereus species feature cylindrical stems with numerous shallow ribs with heavily-spined, closely spaced areoles. In many species, the spines obscure the stems. The overall growth may be erect, shrubby columns or prostrate stems, crawling along the ground as they grow. Flowers are funnel-shaped and the floral tubes feature both scales and hairs to varying degrees in the species. All are night-blooming, but do remain open into the day. As expected with night-blooming cactus, flowers are mostly white and fragrant. Some may be pinkish-to red. Fruits are globular and fleshy.
Examples of Haageocereus cacti:
A few of the twenty-some species in the genus Harrisia are found in cultivation and often grown as landscape plants in warmer climates where they can clamor and sprawl freely. Stems of this species are typically thin and few-ribbed; areoles with several needle-like spines are spaced enough to make the stems easily visible. All species have large nocturnal, white flowers which are fragrant. Floral tubes have bristles or wool and the fruits are round yellow or red fleshy spheres. The fruits are a useful identification key.
Examples of Harrisia cacti:
The genus name Hatiora was made up by cactus taxonomists Britton and Rose in 1923 to honor an earlier botanist named Thomas Hariot. Previous to this time the genus was more sensibly, Hariota, but due to the guidelines of nomenclature, this previous name had to be rejected.
Today, most authors include 5 or 6 species within the genus. They are all epiphytic, meaning they grow in trees in more wet/humid regions. The stems of these species may be either flat and leaf-like or round in cross section. Some growers prefer to use the genus name Rhipsalidopsis for the species with leaf-like stems. They are similar in that new growth and flowers arise from the end of the existing stem segments only. Flowers range in color from yellow-orange to pink to bright red and the fruits are fleshy round or angled.
In cultivation, hybrids of H. gaertneri and H. rosea are among the most popular of all cactus species in cultivation. They are found world-wide in grocery stores and garden centers. They are often sold as “Spring Cactus” or “Easter Cactus” because they often bloom in spring. Although, if grown properly, these plants will flower 2 or more times within a year. Likewise common, but less-so is the species H. salicornioides which is sold as a hanging basket plant for its quaint stem growth. Other species in the genus are quite uncommon in cultivation.
Examples of Hatiora cacti:
Hylocereus is best known for producing exotic, large fruits, known as Dragon Fruit. While all species of the genus have varying edible fruits, that of H. undatus is the primary species found in grocery stores and street markets – particularly in Asia. These fruits are slightly larger than an orange, with red skin accented by green scales.
The species in this genus grow like vines, sprawling and clambering their way up into the trees. Most species are not epiphytic, but root in the ground and climb from there. The plants may branch frequently and grow quite high up exceeding 30 feet (10 meters) thus becoming quite massive. The stems are typically three-angled with wavy or punctuated margins and few short spines if any.
Flowers of Hylocereus are the largest in the cactus family with the largest easily exceeding 12 inches (30cm) in length and diameter. The floral tubes are thick with leafy scales and no spines or bristles or hairs. The flowers are primarily white and fragrant opening at night. Surprisingly, these massive flowers will only remain open for only a few hours on just one night. This combination of large size and short lifespan make viewing a Hylocereus flower a real treat! Although, well-established plants in warmer climates may produce many flowers over the course of several nights.
Examples of Hylocereus cacti:
[I] Types of Cactuses with Pictures
A single species makes up the genus Isolatocereus. Although these plants closely resemble Stenocereus species and overlap geographically. As a result, taxonomists in the past have included the species I. dumortieri in Stenocereus under the same species name S. dumortieri. Differences in form – particularly the flowers – along with DNA research in the late 1990's are support for keeping this species in a separate genus. However, the New Cactus Lexicon, while stating this supporting information, places the species back into Stenocereus with no further explanation.
The plants themselves feature shallow ribs between 5 and 8 on stems up to 6inches (15cm) in diameter. Straight, heavy spines line the ribs in tightly-spaced areoles. The stems feature a bluish-green epidermis which is quite attractive. Overall growth of I. dumortieri is that of a tree branching low with long branches extending to nearly 50 feet (15m). Flowers are greenish-white and nocturnal, but remain open into the day.
The coloring, shape, and spine patterns of this plant make it desirable for cultivation, but the large size makes it more suitable as a landscape plant. This is not to say it isn't found in cultivation, but unless planted in the ground, one is not likely to ever see flowers on this species. In the wild, plants are widespread throughout central to southwestern Mexico.
Examples of Isolatocereus cacti:
[L] Types of Cactuses with Pictures
The Lasiocereus are characterized by having cylindrical stems with numerous ribs, closely-spaced areoles with spines that are clearly visible, but not so numerous as to obscure the stems. Flowers come from woolly sections of the stem that are not developed enough to be a true cephalium. The flowers themselves are tube-shaped, nocturnal and white. The floral tubes feature both wool and bristles and are wide in proportion to their length when compared with flowers of similar plants.
Examples of Lasiocereus cacti:
Lepismium species are either Epiphytic or Lithophytic -meaning tree-dwellers or rock dwellers. They typically grow as hanging masses of many-branched stems that branch off from the middle of the stems (Mesotonic). The stems vary from flat, to angled, to rounded in cross-section. Flowers arise along the sides of the stems and often line the entire length of the stem on both sides. The flowers themselves are relatively small, though generally larger than those in the similar genus Rhipsalis. Several Lepismium species feature colored flowers and other have white flowers, either of these turning into bright colored fruits later on.
Examples of Lepismium cacti:
Leptocereus is a genus consisting of just over a dozen species, all native to the islands of the Caribbean. In cultivation, it is extremely rare to encounter any one of these species. As a result, most cactus growers are unacquainted with the genus except by the occasional photograph and even the internet is short on supply of images.
The plants themselves are mostly sprawling shrubs, but can also form trees up to 30 feet (10m) or more in height. The stems are highly angled, that is, with few large ribs which bear comfortably-spaced areoles that have spine clusters of about 10 spines or so. Some lose spine as they age. The flowers are white or whitish-green and bear spines on raised areoles in most cases. Some species are reported to produce a cephalium.
Examples of Leptocereus cacti:
Leuchtenbergia consists of a single species, L. principis that is quite distinct in shape from every other cactus species. It is immediately recognizable due to its extremely elongated triangular tubercles which reach up to 5 inches (14cm) in length! These tubercles are arranged in a rosette fashion that is reminiscent of an Agave or Yucca. At the end of each of these tubercles is an areole with long, papery, flexible spines. These spines can exceed 8 inches (36 cm) in length. Flowers come from new tubercles in the center of the plant and are bright yellow and easily exceed 2 inches (5cm) in diameter.
Examples of Leuchtenbergia cacti:
Lophophora is a genus of spineless, button-like cacti native to Texas from Presidio county south right along the Rio Grande river to Starr County, Texas. Its range continues south through Northeast and north central Mexico to Querétaro in central Mexico.
Examples of Lophophora cacti:
[M] Types of Cactuses with Pictures
Maihuenia is a genus largely accepted as containing two species which are quite distinct from other cactus. The plants in this genus are so different that they have been classified as the sole genus in the subfamily Maihuenioideae. These plants grow as mats which hug the ground and are made up of segmented short-rounded stems. The stems feature typically 3 spines per areole and also have small rounded leaves which do not fall off as they do in Opuntiads. The flowers come from the ends of the stems and are shades of yellow from near-white to orange. Club-shaped fruits are fleshy and contain bracts.
Examples of Maihuenia cacti:
Maihueniopsis plants form cushions on the ground of tightly-packed stem-segments. Stems are mostly round or globular and several species have large taproots with very little growth above ground. Unlike Maihuenia, the leaves of Maihueniopsis fall away as the new growth matures. Spines may be long and dense, protecting the plants or tiny and tight against the stem. Flowers are mostly yellow, rarely white or red.
Examples of Maihueniopsis cacti:
With nearly 200 recognized species, the genus Mammillaria is one of the largest of the cactus family. For the most part, these species are globose or ball-shaped plants which grow either solitary or in clumps. Some clumps may reach over 3 feet (1m) with many stems. Few species grow much over around 6-8 inches in height by 4-6 inches in diameter. All have nipple-like tubercles with dimorphic areoles on the ends. Spines may be stiff and stout, few or many, bristle-like, hair-like, pectinate (comb-like), and come in a wide range of colors. In the axils, that is between the tubercles, there may be wool or bristles or both or neither.
Flowers come from second-year growth in these axils and often form a ring around the stem. In many species the flowers are small and pink at less than half-an-inch in diameter. Some are small and yellow or white, while a few species have showy flowers which stand on long floral tubes above the plant. In many cases, the petals will feature a darker midstripe. The fruits are typically red, tube-like structures resembling little candies and are edible. To describe so many different species in such general terms does not do justice to this genus.
Examples of Mammillaria cacti:
Mammilloydia candida popularly called ‘Snowball' is a choice, attractive succulent plant with a so dense snowy white, spination, that its body appears almost hidden by spines. Mammilloydia are clearly related to the genus Mammillaria, but their unique seed structure and other anomalies indicates that their overall resemblance to Mammillaria is due to convergence and are usually recognized as segregate genera. However, their true relationship remains unclear. So far: Mammilloydia candida subs. ortizrubiona, connected through the particularly lovely Mammilloydia candida var. rosea, represent the segregate genus Mammilloydia.
Example of Mammilloydia cactus:
Overall, Matucana species are globular or cylindrical plants with shallow ribs and moderate to light spination. The largest maxing out at around 30 inches (75cm), most remain under a foot (30cm) in height. Ribs are distinctly tuberculate and the plant bodies are typically bright green. The flowers of Matucana are quite distinctive and showy. Most are bilateral and stand up above the plant on tall floral tubes that are reminiscent of “cowl vents” on a ship. (The vents that cartoon characters are always jumping into.) Most flowers are red, but may be orange, pink, yellow, or white. Fruits are juicy and round.
Examples of Matucana cacti:
Adult Melocactus are among the most fascinating of cactus in appearance. When young, the plants are quite plain and look very much like one would expect a cactus to look like. They have globose, green stems with multiple ribs. The spines are stout and usually feature a distinct central spine surrounded by radial spines resembling an asterisk. At maturity, Melocactus begin to develop a cephalium, which is a dense mass of areoles that form a bizarre, bristly “cap” directly on top of the stem.
Once this cap is formed, the stem no longer grows, but the cephalium will continue to grow until the plant dies. In rare cases, the cephalium can exceed 3 feet (1m) in height. Most cephaliums are white underneath and orange on top, but may be completely white. It is in this mass of areoles that the flowers are formed. The flowers themselves are quite small, typically pink and come out of the top of the cephalium sporadically or in rings.
Many times, the flowers are not noticed by growers and it is only by the later appearance of fruit that proof of flowering is confirmed. The fruits are much more conspicuous than the flowers and are red or pink waxy-looking short tubes that many have likened to candles on top of a birthday cake. This illusion is further enhanced by the dried flower remains persisting and looking like the wick of these “candles”.
Examples of Melocactus cacti:
Micranthocereus is a genus consisting of slender, columnar stems which grow as sprawling shrubs or single stems. The stems are ribbed with multiple, shallow ribs and feature dense, flexible spines and often have wool. The flowers are small tube-shaped and range from red to orange to white or may be a combination of colors. Flowers arise from a lateral cephalium which is an area of dense areole growth along the side of the stems and is particularly woolly or spiny.
Examples of Micranthocereus cacti:
Miqueliopuntia is a genus consisting of a single species from the coast of Chile. The plants can be likened to the North American genus Grusonia in growth habit and appearance. Miqueliopuntia plants consist of cylindrical, jointed stem segments with prominent tubercles. Areoles occur at the top of each tubercle and have many glochids. Spines in habitat are numerous and shaggy reaching about 3 inches (8cm) and give the plants an untidy appearance. Spine density is affected by the environment and “softer” conditions results in smaller and less numerous spine coverage.
Flowers arise from thick, fleshy floral tubes which closely resemble the stem segments. The flowers may be pink or yellowish green/almost white and are cup shaped. Fruits are globular and heavily armed with spines and/or glochids. Like many Opuntiads, the fruits themselves can be rooted and grown into a separate plant.
Examples of Miqueliopuntia cacti:
The four species of Myrtillocactus are all similar in that they are tree-like, much-branching plants with few (4-8) prominent ribs. Typically the ribs features a single, thick, long central spine and only a few thick, short radial spines or the areoles may be spineless. Flowers are quite small at less than an inch (2.5cm) and have short floral tubes which keep the flowers fairly tight to the stems.
An unusual feature of Myrtillocactus is that the areoles may produce multiple flowers. The flowers are a greenish-white color, waxy and somewhat translucent. Large sections of the ribs will feature flowers all at once and later give rise to blue-berry-like fruits which are very tasty and have been used by native people of Mexico for centuries and are still harvested today. The fruit often goes by the common name “Garambullo” in the local markets. The fruit has also been likened to Bilberry (Vaccinium myrtillus) and true Myrtle (Myrtus communis).
Examples of Myrtillocactus cacti:
[N] Types of Cactuses with Pictures
Neobuxbaumia occurs in the eastern and southern parts of Mexico. In habitat, these plants form impressive cactus-forests which stretch over the hills. There are 8 or 9 species in the genus depending on the author and they are all large tree-like species which reach nearly 50 feet (15M) in height. Stems are columnar with numerous ribs and eventually branch with age and size. As with most tree-like cactus, the juvenile plants vary considerably in appearance due to the proportions of spines/rib size to overall stem size.
Younger plants are typically more heavily spined while adult plants will lose spines on the lower parts of the stem or at least the spines are dwarfed by the stem size. Ribs may be somewhat tuberculate and spines are not especially heavy and do not obscure the stems. Flowers are bell-shaped and may be white or pink; nocturnal, often bat-pollinated. Fruits are round with spines and split open when ripe with a white pulp.
Examples of Neobuxbaumia cacti:
Neolloydia is a genus of cacti. The genus is uniquely found in the dry scrub areas of southern Texas (Big Bend) and the Chihuahua Desert of Northeast Mexico.
Examples of Neolloydia cacti:
Plants are tree-like, branching close to the ground or on a single trunk. Stems are ribbed with 4 to 8 ribs that have wide intervals between them.
Flowers are funnel-shaped and white to pinkish. The floral tubes have scales and felted areoles and may have bristles. Fruits are round and retain the areoles. Seeds black and pitted.
In cultivation, N. herzogiana was quite common for a time being available through large commercial growers worldwide, but it has become less so. It is a fairly easy plant to grow, but because of their large size, a flowering specimen is only possible where it can be grown in the ground. N. arequipensis is very seldom found in cultivation and only by those who have intentionally sought out the species rather than by casual acquisition.
Examples of Neoraimondia cacti:
A small genus of two species, Neowerdermannia is a genus of spiny globose plants which are very similar to the genus Gymnocalycium. Flowers are bourne near the apex and have naked floral tubes with scales – eiter white or pink. The fruits are globose and dehiscent.
The body features ribs which are not clearly defined and broken into rather pronounced tubercles. Areoles are small at the top of the tubercles (not the ends) and give rise to as many as 20 stout spines which may be curved or even hooked.
The plants in this genus are found in Argentina, Bolivia, Chile, and Peru, though apparently not in great numbers. It is even more scarce in cultivation and grown by enthusiasts, but not commercially.
Examples of Neowerdermannia cacti:
[O] Types of Cactuses with Pictures
Obregonia (Artichoke cactus) is one of the highly sought-after cactus from Northern Mexico which are not found in mass-production at large commercial nurseries, but are readily available through specialty cactus nurseries.
The genus is comprised of a single species which is unique in appearance to that of other cactus species and therefore instantly recognizable. Stems are solitary flattened globose shaped with triangular tubercles. The tubercles are arranged in a spiral and give the plant an appearance similar to an artichoke. Areoles are small at the tips of the tubercles and weakly defended by 3 or 4 small spines. Flowers are funnel-shaped, white with yellow stamens and come from the top-center of the plant.
Examples of Obregonia cacti:
Opuntia is the most widespread of all genera in the cactus family. The genus occurs naturally throughout North and South America from as far north as Canada, through the Caribbean, and down into Argentina. With man's help, however, this species can now be found world-wide where it has escaped cultivation and become naturalized even to the point of being classified as a noxious weed.
Opuntia are easily recognized by their flat paddle-shaped stem segments called cladodes that grow one on top of the other. The edge and flat surfaces of these cladodes are covered with areoles that always have tiny, easily detached spines called glochids. Many Opuntia species have large, formidable spines in addition to the glochids, but some are armed only with masses of glochids. These have the appearance of being soft or fuzzy, but anyone who does touch them immediately regrets doing so. The small size of the glochids does not cause much pain, but is rather highly irritating. As such, these have been collected for use in the making of itching powder.
Opuntia flowers are typically yellow, sometimes pink, and rarely white or anywhere in between these colors. Flowers are cup-shaped and do not have floral tubes, but instead the pericarples resemble round, extensions of the cladodes. It is impossible to determine if new growth is going to be a flower or a new cladode as they are identical when first appearing – often covered with cone-shaped deciduous leaves.
If a rounded pericarple, this later becomes the fruit and may turn a bright red color or stay green. Some Opuntias have very juicy, fleshy fruit called “tunas” that are harvested and turned into candies or jellies. Similarly, cladodes when still young and tender are harvested and eaten as a vegetable – particularly in Mexico under the name Nopales.
Examples of Opuntia cacti:
Oreocereus could possibly be considered the South American counterpart to that of Cephalocereus in the Northern Hemisphere. They are similar in that they are predominantly short-columnar species which are covered in thick white wool or hair. Some species in this genus have so much hair that it completely obscures the stems underneath. While the wooly covering gives them a soft appearance, closer examination reveals sharp spines extending beyond the wool.
A number of Oreocereus species are found in cultivation, grown primarily for the dramatic white hairy stems and puts them all under the common name “Old Man Cactus” or “Old Woman Cactus”. Stems underneath are ribbed and notched between areoles.
Flowers are not uncommon even in cultivation and are usually bright red or orange and quite striking. Flowers are bilaterally symmetrical and similar to that of the genus Cleistocactus under which at least once species was previously placed. The style and stamens protrude beyond the pericarples. Fruits are rounded and fleshy.
This genus is found at higher elevations – typically 10,000 feet or more in Peru, Chile, Bolivia, and Argentina. The white wool covering, no doubt provides protection against the intense UV at these elevations.
Examples of Oreocereus cacti:
Another small genus of high-elevation plants from the Andes mountains in Peru. Oroya species are barrel-shaped with many ribs that are topped with usually-dense pectinate spines. The spines typically bright yellow or reddish brown which creates an unexpectedly striking appearance. Stems are solitary and not large – growing up to 13 inches (32 cm) high, and 9 inches (22 cm) in diameter.
Flowers are borne near the top, often in a ring and point straight up. They range in color from bright-yellow to brilliant pink/red. Flowers are relatively small at less than an inch long and radially symmetric with recurved outer perianth parts. Fruits are small, rounded and fleshy.
Examples of Oroya cacti:
Ortegocactus is a cactus genus that consists of only one species that was discovered relatively recently in the second half of the 20th century. It grows in a very small area on limestone in Oaxaca, Mexico.
The plants begin as solitary stems which do not exceed 2 inches in diameter and as they age, form small clumps of several stems. The stems are tuberculate with gently-rounded tubercles topped with small areoles. Sines are grey-white with black tips. The overall appearance of these plants is more like a blob rather than a tidy round ball – especially when dehydrated.
Flowers are bright yellow and funnel-shaped at the top of the stem and feature a green stigma.
An interesting characteristic of this plant is the beautiful gray-green dermis, which is notably porous and has a skin-like appearance. Like so many of the small species of Mexican cacti, Ortegocactus is highly prized by collectors. However, as these plants age, they tend to develop rust-colored spots on them even in the care of the most accomplished growers.
Examples of Ortegocactus cacti:
[P] Types of Cactuses with Pictures
The genus Pachycereus contains some of the largest growing cacti of all. One species is reported to reach a height of 82 feet (25m) in height! Although not all species are quite that large, all of them are columnar and feature tree-like or shrubby growth with relatively large branches.
Stems are ribbed and may be either a blue-green or bright green color. Like most columnars, there is a considerable difference between smaller seedling plants and the larger mature plants. Often smaller plants will be heavily armed with spines which are reduced or even absent on older stems. A few exhibit a pseudocephalium – that is an area of extremely dense spines, which gives rise to the flowers.
Flowers are small tubes or funnels up to 4 inches long. The floral tubes feature scales and may be bare, fuzzy, or spiney. Fruits are dehiscent and fleshy.
Two species, P. pringlei and P. marginatus are extremely common in cultivation. The former is a native of Baja California and is often confused with the well-known “Saguaro”, while the latter is grown in Mexico in tight lines as a “living fence”. Perhaps 2 or 3 other species are found in a limited number among collectors or grown in yards near their native habitat. However, the remaining species are almost non-existent in cultivation.
Examples of Pachycereus cacti:
Species currently and historically included in the genus Parodia are very popular in cultivation. Many of them are easy to grow, have intriguing stems and spines and flower easily with brightly-colored flowers. This in combination with their relatively small size ensure that nearly all cactus growers will have some representative of this group. While advanced hobbyists may grow many of the various species and subspecies.
Plants in this genus are globose or short cylinders that may be solitary or forming clumps. Stems are typically ribbed, but may also be strongly tuberculate. Spines may be thin and few or dense and stiff.
Flowers in all species arise from fuzzy buds, typically with bristles, at the apex. Flowers are cup-shaped and point straight up. In general, the plants that have been affiliated with other genera as mentioned above, have yellow flowers between 1 and 2 inches in diameter. The Parodia species often have orange to red flowers, which may be only 1/4 inch or so in size. However, this is hardly a hard and fast rule and there are exceptions in both cases.
The stigma on all species is pronounced and often is a highly contrasting color with long lobes which can be useful for identification. Fruits are fuzzy, sometimes spiny and usually dry, clinging fast to the plant until long after the small black seeds begin to spill out. Seeds tend to vary and is a major taxonomic sticking point.
Examples of Parodia cacti:
Pediocactus is a genus of cacti. The genus comprises between 6 and 11 species, depending upon the authority. Species of this genus are referred to as hedgehog cacti, though that name is also applied to plants from the genera Echinocereus and Echinopsis.
Examples of Pediocactus cacti:
Pelecyphora is a genus of cacti, comprising 2 species. They originate from Mexico. Pelecyphora is known for its medicinal properties and may have been utilized as a psychoactive in the same way as Lophophora williamsii. It is known as “Peyotillo”.
Examples of Pelecyphora cacti:
Plants in the genus Peniocereus are mostly sprawling stick-like plants from the Southwest United States and Mexico. In the wild, the plants are hardly noticed as they grow among shrubs and themselves appear to be simply dead branches. A number of the species feature large underground tubers which may reach 70 pounds or more. The flowers, by contrast, are as showy and prominent as the stems are nondescript and obscure. White and nocturnal in most species, rarely red, the flowers feature long, slender floral tubes, with prominent areoles and spines or bristles – often fragrant. Fruits are typically large and juicy with black seeds in white or red pulp.
Examples of Peniocereus cacti:
Pereskia is a cactus genus that is most unlike all other members of the family. Except for the defining characteristic of spine-bearing areoles and some floral characteristics, the plants in this genus are anything but cacti.
This is a tropical genus that grows as typical deciduous trees or shrubs that consist of a woody trunk and branches with flat leaves. Some people have insisted that it is not correct to say that “all cacti are succulents” because of the genus Pereskia, however, many have some form of root succulence or to a lesser degree in the stem and all of them produce thicker, rubbery leaves. These leaves are fleshy like that of a Portulaca and not “papery” like those in an Oak or a Maple tree.
In the wild, these plants are typically found among other trees and shrubs and their presence is not immediately apparent. In flower, the shrubs can be quite brilliant and individual flowers are reminiscent of a wild rose, hence the common name sometimes used: Rose Cactus.
Due to the large size and tropical nature of these plants, they are seldom found in cultivation. P. grandiflolia is the most common species to be found in cultivation, if anything.
Examples of Pereskia cacti:
Plants are ribbed, short columns which produce bright-pink tube-shaped flowers near the stem tips. An endemic of Brazil, these plants are found in limited populations in the wild.
Examples of Pierrebraunia cacti:
The genus Pilosocereus was known as Pilocereus up until 1954 when it was renamed due to a discrepancy found according to the rules of botanical nomenclature. This earlier name meant felted-cereus. Both names refer to the very hairy areoles on the stems – at least the mature flowering portions of the stems. Many of the species in the genus feature spectacular blue-colored stems, but may be green.
Plants are either shrubby or large, tree-like. Flowers are tube-like and the floral tubes and unopened buds are often very blue in color. The perianth parts of the flower are often white or pinkish-white with many stamens and a protruding style. Floral tubes have scales and are smooth and spineless. Pollination is done by bats. Fruits are fleshy and contain seed and pulp.
Examples of Pilosocereus cacti:
Two tree-like species from Southern Mexico make up the genus Polaskia. A columnar cactus which branches as it ages with many branches on a short trunk. Stems are ribbed with fairly shallow spaces between ribs. Areoles are spaced 2 or 3 cm apart along the ribs. Spines are short and stout, numbering 8-10 radials and one central. Spines may not be present at all – especially on mature plants. Flowers are widely-opened cups of pinkish white or yellow-green – with or without spines. Fruits small, fleshy berries.
Examples of Polaskia cacti:
Pseudorhipsalis is often included in Disocactus. It is epiphytic, many branched, and elongated with flattened, serrated leaves. In its early life, it stands erect, but soon becomes prostrate. It produces numerous flowers.
Examples of Pseudorhipsalis cacti:
Most unique among the cactus family is that the flowers of Pterocactus are embedded in the stems to such an extent that it appears the entire stem is merely a long floral tube. The flowers come right out the end of a stem, which terminates the stem growth as a result and a new stem will then branch off the side and grow until it, in turn, results in a flower.
If the flower is successful, the end of the stem will develop into a dry fruit that later splits open and reveals seeds with wide wings that are also unique within the cactus family. In fact, the seeds look very much like those of an Elm (Ulmus) tree. Furthermore, Pterocactus species feature large tuberous roots, which continue to grow, while the stems may fade away and be replaced by new ones over time.
Examples of Pterocactus cacti:
The genus Pygmaeocereus features small, cylindrical stems that form clumps. The stems have shallow, tuberculate ribs with many spines that are spreading and not fierce. Flowers are nocturnal, white and open on the end of long, thin floral tubes that have scales and are hairy.
In habitat, this genus is restricted to Peru – particularly in the fog zone along the coast. In cultivation, the species is grown among more serious cactus collectors, but not grown commercially.
Examples of Pygmaeocereus cacti:
[Q] Types of Cactuses with Pictures
The single species in the genus Quiabentia is a leafy cactus that grows like a typical deciduous tree. It generally forms a single trunk with a crown of branches that feature broad, flat leaves which are somewhat succulent. In this way, it is similar to either Pereskia or Pereskiopsis, although it is thought to be more similar to Pereskiopsis in that it contains glochids in the areoles. Flowers are red or pink and rise from the stem tips, and similar to the flowers of Pereskia. Floral tubes have spines and glochids. Fruits are fleshy with large round seeds.
Examples of Quiabentia cacti:
[R] Types of Cactuses with Pictures
The genus Rebutia is one of the most popular in cultivation. Several species are produced on a large scale commercially and found in garden centers around the world. The plants in this genus are small, globose or flattened-globose plants that usually form a small clump. Stems are usually tuberculate in poorly-defined ribs. Spines vary widely even within plants of the same species.
They are vigorous growers which flower quite readily with typically a large number of relatively large, showy, brightly-colored flowers which arise from areoles, usually around the lower portions of the stems. Flowers are funnel-shaped with floral tubes that often extend and curve upwards over the plant. Floral tubes feature scales and may have hairs, but not spines.
Examples of Rebutia cacti:
Rhipsalis is a genus of epiphytic cacti. They are typically known as Mistletoe cacti and most occur in Brazil. The scientific name derives from the Ancient Greek term for wickerwork, referring to the plants' habitus.
Examples of Rhipsalis cacti:
[S] Types of Cactuses with Pictures
This small genus of epiphytic cacti is well-known worldwide as the “Christmas Cactus“. Not all species in the genus are considered “Christmas Cactus”, however. The true “Christmas Cactus” is actually a hybrid produced in Europe which has been widely propagated through cuttings for at least 150 years – which is Schlumbergera xbuckleyi.
More recently however, hybrids of the species S. truncata have been produced on a massive scale commercially and can be found in nearly every “box store” during the months of November and December. These are often sold under the name “Christmas Cactus”, but should more properly be referred to as “Thanksgiving Cactus”, as they tend to bloom most in late November. Another genus name was used up until the 1950's – Zygocactus for some species which belong to Schlumbergera. As is often the case in cultivation, old names die hard and many nurseries still label the plants as Zygocactus.
Stems are either leaf-like segments which grow from end-to-end, or in two species grow similar to Opuntia with more rounded stems segments covered with areoles and small spines. Flowers are showy, tubes with recurved petals and may be radially or bilaterally symmetric. Usually bright red or pink – often bi-colored. Fruits are small berries.
Examples of Schlumbergera cacti:
Plants in this group are native to the Southern United States and Northern Mexico. Here they grow in often very-restricted populations. Where they experience a surprising range of climate conditions. However, despite the harsh environment where these plants seem to thrive, they are notoriously difficult to grow in cultivation. Most people who do succeed in keeping these species do so with a pure mineral substrate with no organic material.
The plants themselves are relatively small globes or cylinders usually with tuberculate ribs. Most have a dense cover of spines with a prominent hooked central spine. Flowers arise from the apex of the plant and point straight up. They are funnel-shaped and range widely in color from pink to yellow to greenish to white and even brown. Fruits are similar to that of Ferocactus, however the scales tend to have small tufts of wool in the axils; dehiscent.
Examples of Sclerocactus cacti:
It is named after the Greek moon goddess Selene as the flowers open at night. The various species that make up the genus Selenicereus are similar in that they are vine-like, climbing plants. Primarily epiphytes, some also grow on rocks. The stems may be mostly round in cross-section, to sharply angled, to flat-jagged, almost fern-like. Some species are spineless, while other have tiny hairlike spines, and still others with more formidable protection. Ariel roots are common along the stem which aid in climbing.
The flowers are night-blooming and rather spectacular and typically fragrant. Some exceed 12 inches in diameter and most have long, slender floral tubes that have scales, hairs, bristles or spines. Fruits are fleshy with persistent spines. Most flowers are all white, some are white in part with red or yellowish outer perianth parts.
Examples of Selenicereus cacti:
A number of species of the genus Stenocactus are popular in cultivation. The plants are globose and remain relatively small making them very manageable in pots. Additionally, they grow easily and flower readily – often one of the first in a cactus collection to flower in the spring. In addition to their ball-shape, most species in this genus have unique fin-like ribs that are very numerous. This gives them a look reminiscent of undersea coral.
Spines are usually present and prominent, but not to the point of obscuring the stem. Flowers arise at the apex and are often white with a wide, dark pink midstripe, but can be a plain creamy white. This genus is native to the Chihuahuan desert in Mexico.
Examples of Stenocactus cacti:
Stenocereus is a genus comprised of primarily large, shrubby or tree-like columnar cacti. It is widespread from the Southern United States, throughout Mexico, Central America, the Caribbean, and into Northern South America.
Stems are cylindrical and often have numerous ribs. Ribs are slightly notched at the areoles with needle-like spines. The flowers are stout, funnel-shaped with recurved outer petals and prominent stamens. Floral tubes are spiny, but the spines drop off as it matures into fruit.
Examples of Stenocereus cacti:
There is but a single species in the genus Stetsonia and it is a large tree-like cactus with often forms a well-defined trunk and numerous branches. It is one of the most widely cultivated of all large, columnar cacti. Second perhaps to the enigmatic Cereus peruvianus. However, unlike the latter, Stetsonia is often sold at box stores while still small plants and are grown in pots rather than in landscapes. As a result, it is rare for cultivated plants to get the chance to bloom in these conditions. However, they do produce extremely long spines which certainly lends to its popularity along with the common name of “Toothpick Cactus”.
Stems have many shallow ribs, with needle-lick spines, branching with age and size, but sometimes branching early on. Flowers are while funnel-shaped opening at night and remaining open into the day. This genus is found widespread in southern South America.
Examples of Stetsonia cacti:
Strombocactus disciformis is a rare cactus with strong, turnip-like root and small, sunken, roughly spherical stem covered with spirally arranged overlapping tubercles, each with a spine-bearing areole at its tip. The stem is up to 3.2 inches (8 cm) tall, blue-green with a grayish tinge.
Examples of Strombocactus cacti:
[T] Types of Cactuses with Pictures
Tephrocactus is a small genus in the subfamily Opuntioideae which is endemic to Argentina. Like other members of this group, Tephrocactus does have glochids, however, they are uniquely sunken into the areoles in this genus. Spines may be long, dense and needle-like or thin and papery or absent. The stems grow in very distinct segments, but unlike the flat-pads found on the genus Opuntia, the segments of Tephrocactus are round. This can be either in short cylinders, egg shaped, or even spherical. Thes segments typically grow in a slightly zig-zagged stack. Flowers are white in most species or pinkish, sometimes yellow, and in one case red.
Examples of Tephrocactus cacti:
Thelocactus is comprised of a dozen species that are found primarily in the Chihuahuan desert of Texas and Mexico. The species have feature small globose or short cylindrical stems that are solitary or form small clusters. The stems have ribs that are strongly or entirely tuberculate and are often topped with stout, needle-like spines, which are hooked in some species.
Flowers are white, pink, or yellow and often are a combination of colors, either in concentric rings or strips. The flowers are usually large in proportion to the stems and come from the top of the plant. Flowers may also continue during the entire summer.
Examples of Thelocactus cacti:
Another small group of Opuntiads from South America, Tunilla was rarely found in cultivation in the past, but is becoming more common as interest in the group is growing. The stems of this genus can be flat jointed cladodes (or paddles) or rounded segments. These are covered with areoles that contain glochids and spines. Flowers are red or yellow and various colors in-between – very vibrant.
Fruits are dihiscent with a single slit. The genus can be found in Argentina, Bolivia, Chile, and Peru.
Examples of Tunilla cacti:
Its name comes from the Latin turbinatus meaning top-shaped and the Greek carpos meaning body – a reference to the top-shaped growth of the stems.
The plants in this genus have small stems, often growing hidden in the soil in habitat. In cultivation, the plants are often solitary globose stems with distinct tubercles. Spines vary considerably from species to species. Flowers arise from the stem tips and range from white to dark pink.
Examples of Turbinicarpus cacti:
[U] Types of Cactuses with Pictures
Three species from Brazil make up the genus Uebelmannia, these plants feature globose, to cylindrical stems that have distinct ribs lined with spines. The epidermis of the plants has a granular texture to it and can be a bright green, waxy-gray, or even dark purple in color. The spines typically stand in contrast in bright white, golden, or black coloring with areoles forming a continuous line along the ribs. These characters, while hard to describe, give the plants a most striking and unique appearance. The flowers, however, would not be considered anything special among the cactus family as they are small little yellow funnels which come out near the stem tip.
Examples of Uebelmannia cacti:
[W] Types of Cactuses with Pictures
Most of the epiphytic “jungle” cacti genera have at least a few members which are common in cultivation. This is not so with the genus Weberocereus, where only a few specimens can be found in cultivation grown by an occasional collector with an interest in the uncommon. In the wild, the species are found in primarily in Central America with limited extend up into Mexico and down into Ecuador.
The plants are vine-like clamoring, putting out arial roots as they grow. Stems are segmented and round, angled, or flattened. Areoles are small and spines few or absent. The flowers are nocturnal, funnel-shaped mostly white, with some pinkish or yellowish.
Examples of Weberocereus cacti:
[Y] Types of Cactuses with Pictures
Named in 2001, the genus Yavia is one of the most recently described genera in the cactus family. It was found growing at over 12,000 feet (3700m) elevation in a harsh, dry environment with very rocky soil. The single species is a small globular plant that consists primarily of a single stem, but may clump, especially when grafted. Ribs are present, but hardly noticeable beyond the rows of fuzzy-white areoles that feature very small reddish-brown spines. Flowers are pink with a short, thick floral tube.
Examples of Yavia cacti: