There are just two species of tiny plants in the genus Epithelantha. Since there is a lot of variety in spination, many species have been identified; however, most have chosen to focus on just two and refer to the variants as subspecies. This appears to satisfy both taxonomists and hobbyists in the majority of cases. Both plants have stems that are only little larger than 2 inches (5 cm) in diameter and not much taller than that. The spines, whether they are long or short, are white and develop from tubercles much like Mammillaria.
The flowers, on the other hand, emerge from fresh growth from the spine-producing areoles at the tubercle’s tip. This characteristic distinguishes Epithelantha from Mammillaria clearly. The blooms themselves are tiny, delicate-looking funnels that are light pink or white. While the berries of Epithelantha are fairly spectacular, the little blossoms may go practically missed. The vivid red color of these fruits, which resemble long tubes that shoot up like birthday candles, contrasts sharply with the white spines.
Epithelantha cacti examples:
Eriosyce
A genus of South American species known as Eriosyce are primarily globose or somewhat cylindrical. Early taxonomies had grouped them together in the genus Echinocactus because of their similarly shaped flowers and circular, ribbed stems, which are typically densely armed with dense, sharp spines. However, the genus has been around since Rudolph Philippi discovered it in 1872, and for the past century or more, experts have all agreed that these plants are not Echinocactus.
Despite this, the species of Eriosyce included in this default listing are still regarded as being unique. Neoporteria and Neochilenia are the two main names that are still in use today, with Islaya being used as a third name for a monotypic genus of a single species. In cactus grower’s collections and the cactus nursery industry, all three of these names are still frequently seen on tags.
Both the names Neochilenia and Neoporteria have been given to numerous species at various points in time. Neochilenia, on the other hand, is distinguished by short to nonexistent spines and funnel-shaped flowers that, when fully opened, allow the inner section of the flower to be seen plainly. Neochilenia has hairy flower tubes that later develop into hollow, meaty fruits. In contrast, Neoporteria species typically have thicker, longer spines than Neochilenia species.
Bright pink flowers with yellow interiors have a more tube-like form since the inner petals are largely closed. Even when completely opened, the interior sections of the blooms are still hidden by petals because the outer petals flare out and prevent the flower from having the same tube-like appearance as other cactus genera. The fruits are similar to those of the Neochilenia group and the floral tubes may contain a little fuzz. The plants that are referred to as islaya are extremely diverse and are found in Chile and Peru.
The entire genus Eriosyce is made up of hardy South American desert survival. Many take place at high altitudes where they are exposed to intense UV and large temperature changes. The plants will become dormant till the weather is suitable once more in order to cope with the tough environment. Even within the same species, there is a significant difference between plants growing in their natural habitat and those grown in a controlled environment.
Plants grown in cultivations with few spines and rounded, plump stems may become flattened and completely covered with spines. There have been a ton of synonymous names published as a result of this variant and the variations mentioned above.
Illustrations of Eriosyce cactus
Escobaria
Small, tuberculate, globose to cylindrical, single or clumping stem species are found in the genus Escobaria. Many of the species were formerly part of Mammillaria and Coryphantha. The inclusion in Mammillaria was mostly brought about by the plants’ general morphology, particularly the presence of tubercles. In contrast to Mammillaria, Escobaria flowers from top new growth and lacks dimorphic areoles, which means that the areoles do not have different portions for creating spines and areoles.
More subtly, and mostly in the seeds, Coryphantha differs from other species. In contrast to Coryphantha’s reticulate (crisscrossed) seeds, those of Escobaria are pitted (foveolate). Escobaria and Coryphantha can be distinguished from one another using more general rules than just the need for the seeds. Other characteristics include the absence of extrafloral nectaries, fringed blossom margins, tubercles that cork and fall off with age, and smaller, generally pink flowers.
Some apparently like plants have been transferred from the genus Escobaria to a different one called Acharagma because they lack the grooved tubercle that distinguishes Escobaria.
Escobaria species come in a variety of cultivars, but the species that can withstand low temperatures stand out the most. While many species originate from Mexico and the Southern United States, where it is warmer, two species in this group have a range that extends all the way to Canada. Gardeners love to grow these northern plains species in their cold-tolerant gardens to break up the monotony of otherwise Opuntia-filled beds. Cuba’s island is home to another species.
Illustrations of Escobaria cactus
Espostoa
About a dozen species from Ecuador, Peru, and Bolivia make to the genus Espostoa. They are columnar plants with stems that resemble the skyline of a large city since they mainly branch at the base. The most distinctive aspect of Espostoa is its profuse, white “hair,” which is found in all species and fairly dramatically covers the stems to give them a velvety, fuzzy appearance. However, this is only a trick since behind the silky hairs are a number of sharp spines placed on numerous tiny ribs that round the columns. In some species, the main central spine extends much past the hair making their dangerous presence clear.
Espostoa species are known for their fuzzy white hairy look, which makes some of them very well-liked for cultivation. Large commercial producers often sell the plants as 6–12-inch stems. These plants do not, however, grow in pots with quite the same vigor as they would in the ground because they are huge columnar species. Plants frequently quickly fill their containers, becoming “pot bound,” and after that, their development grinds to a halt. Because of this, these plants rarely, if ever, achieve maturity, failing to generate the cephalium and failing to flower as a result.
On the other hand, people who live in warmer regions and have the ability to plant the species directly in the ground may really have plants that grow in attractive clusters of stems that eventually bloom.
Illustrations of Espostoa cactus
Espostoopsis
Espostoopsis shares many characteristics with the genus Espostoa, as the name suggests. The distinctions are not immediately noticeable, save from the fact that the one species in Espostoopsis is geographically disjunct because it is native to Brazil rather than western South America. Interestingly, despite their striking similarities, taxonomists have never classified this species as Espostoa, according to further research. This isn’t due to the fact that it was always a distinct species; prior to 1968, it was included in both Austrocephalocereus and Coleocephalocereus.
Espostoopsis flower tubes are naked, unlike Espostoa, which is why Coleocephalocereus and Micranthocereus are being compared. Fruits and seeds are less definitive, in part due to how variable they are within Espostoa. Some species produce shiny, smooth seeds, while others produce rougher, even tuberculate, seeds. The seed of Espostoopsis is tuberculate and black. The variations in flowers cause some visible variations in the fruit stalk.
Whatever the case, the genus’ sole species is a low-branching columnar with several ribs. The white woolly hairs that coat the stems and give birth to the core spines that protrude far beyond the hairy covering giving it a woolly appearance. A lateral cephalium gives rise to white, bell-shaped blooms.
Espostoopsis is a well-known cultivar, however it seldom reaches maturity in pots and is primarily grown for novelty reasons because of its hairy appearance.
Espostoopsis cactus examples:
Eulychnia
In order to fully appreciate the Eulychnia genus, one needs have some knowledge of its habitat. These fairly huge plants, which may grow up to 23 feet (7 meters) tall, are found growing in the deserts near the Chilean and Peruvian coasts. These deserts receive little to no precipitation, and the vegetation there is sustained by condensation caused by the region’s strong and frequent fog. Species of Eulychnia occur in this region as tall shrubs or trees with numerous branches.
Numerous long spines placed on tuberculate ribs cover the stems of the plants. The circular floral tubes have scales, wool, or all three coverings, and when the flower opens, they resemble a ball that has split open on one side.
The cultivation of Eulychnia is uncommon, and it appears that only collectors with a particular interest in the genus grow this plant.
Illustrations of Eulychnia cactus
How can I determine the type of cactus I have?
The physical characteristics of each cactus should be used as a starting point when distinguishing one from another. Some distinguishing physical characteristics to watch for are:
The Leaves
One essential aspect you may want to consider is the cactus plant’s leaves. Do your plants have any spines? You can determine this by examining their leaves. A leaf with spines will have needle-like, sharp edges, while a leaf without spines will have rounded edges. The color and shape of your cacti plant’s leaves can also provide useful information.
Chlorophyll and carotenoids, which are photosynthetic pigments, can be used to determine the color of leaves. Carotenoids give the plants their characteristic colors, whereas chlorophyll is in charge of receiving light energy from the sun and storing it as chemical energy.
Your cactus plant type may also be determined by the shape of the leaves. Succulent plants often have spines and needle-like leaves, whereas flat-leaved plants are typically stronger in nature since they can endure severe situations better. For instance, the leaves of a barrel cactus grow straight, whereas the leaves of a saguaro cactus are flat.
Similar to the shape and color, the different needle styles can also be used to identify the type of cacti you have, albeit the results are not always reliable. The more hardy and leafy kinds will typically have flat spines, whilst the more succulent and squishy forms would typically have needle-like spines.
How high can they grow?
When determining the type of cactus you have, you might also want to consider its height. Because plants that thrive at higher elevations typically have longer roots than those that do not, height and altitude can be utilized as a determining factor when choosing your plant type. The Saguaro Cactus, which may often reach heights of 50 feet, is the tallest of all succulents. Hedgehog and pereskia, on the other hand, are little kinds that rarely grow taller than six inches. You can tell what kind of cactus plant you have by just measuring the height of the plant.
Shape and coloration
When there are no spines or leaves to go by, a cactus’ shape and color can also be utilized to determine its type. Shape typically gives some hints about the plant’s requirements for the climate, which in turn may give more information about the nature of the plant.
Although there are so many different kinds of cactus that you can identify, you might not be able to do so just by looking at it because of its color. Another spiny variety may have a green-brown body, whereas a white-spined barrel cactus may have green. The dwarf saguaro’s yellowish hue stands out sharply from, for example, the brown spines on a barbed wire cactus.
As you can see, there are a lot of physical characteristics to watch out for that could reveal what species of cactus plant your plants are. One piece of advice is to explore further if you notice something peculiar or unusual about a particular species because it might be what you’ve been looking for.
How are its flowering style and pattern?
The way a plant blooms is another physical characteristic that will reveal whether it is a terrestrial or epiphytic plant. While terrestrial plants have roots and require direct connection to soil, epiphytes are plants that thrive in humid regions with little soil contact and depend on other plants for nutrition.
Another sign of a cactus’ kind is the way its flowers are arranged. The saguaro and barrel both feature radial patterns, while the hedgehog is another plant with radial patterns but more elongated ones. A species that forms columns, like the cardon, may have vertical stripes or zigzags with contrasting color patterns.
The most likely form of cactus you have is a cardon if it is columnar and has vertical stripes of contrasting colors. On the other hand, if your cactus has radial patterns and spines, it is probably either the barrel or saguaro type.
Although it’s not always reliable, the color of the flowers might also give you a hint about what kind of cactus your plant is. For instance, a hedgehog may have yellow blooms, or a kind of flower with a red top may be a cardon.
What about the seeds?
Depending on their environment, different cactus species generate different seeds. For instance, the Saguaro cactus produces smaller, fleshier seed pods, whereas the hedgehog produces much larger, spiky fruit. While the cardon is known to produce seeds that are round and glossy, some varieties, like the barrel cactus, will have a more oval or spherical appearance.
These various seed pod varieties can provide you hints about the kind of cactus you might grow in your garden. Perhaps after a lengthy development period, your plant that you’ve had for a while isn’t blossoming or generating any flowers? Even before planting, it may be quite beneficial to look at the seeds, since they might provide important details about the type of plant. If your cactus isn’t flowering or generating any flowers over a lengthy time of growth, it may not be blossoming due to its type or the climatic circumstances that type loves. Different cactus species generate different seed pods.
How may a plant be identified as a cactus?
You might be in the desert, your neighborhood botanic garden, or your quirky neighbor’s eccentrically planted yard. You take a step back and immediately experience a severe leg discomfort. You turn to find a plant invading your personal space and piercing your flesh with its pointed spines and swelling stems. Instead of cursing, you choose a gentler word. Crazy cactus!
Almost any plant with swollen, succulent sections—especially if those parts have uncomfortably sharp edges—is usually referred to as a “cactus.” The armored succulent plants, however, are frequently no more closely related to onions or apple trees than they are to cacti. There are numerous spiky, thorny succculents that do not fit the definition of a cactus because they do not belong to that particular family of plants.
You can find many instances if you quickly browse Flickr’s history. For instance, this clumping aloe ground cover came up as the very first result in my morning search for the term “cactus,” with the label “cactus green.”
Aloes have the same succulent shape that many cacti have, and some of its species have strong spines. However, they are not closely related to cacti. It is believed that between 130 and 170 million years ago, during the Jurassic, aloes and cacti shared a similar progenitor. In terms of our most recent shared ancestors, aloes and cacti are far more closely linked to you and I than they are to aardvarks.
Another plant that is frequently mistaken for a cactus is an agave, as seen in this wonderful image titled “cactus in black and white”:
Spines, succulent, but not a cactus. Compared to cactus, agaves and aloes are rather closely related to one another because they both belong to the Asparagales order. The taxonomic unit above “family” is called an order. Aloes and agaves are still only very distantly related to one another. While aloes are often found in Africa, Arabia, and several nearby islands, agaves emerged in the Americas.
What else is referred to as a “cactus” that isn’t? Well, for starters, yuccas and Joshua trees. Succulents without spines like Lithops, Echeverria, Haworthia, and Stapelia frequently have incorrect names. Even though ocotillos are not extremely succulent, they are frequently referred to be cacti.
The succulent Euphorbias, some of which can accommodate persons who would never mistake a yucca for a cactus, would have to be the largest group of plants incorrectly referred to as “cacti”:
Although I would have had to look again, the photographer here correctly identified the plant.
We have a variety of unrelated plants, but they all tend to have two things in common: most of them are succulents, and most of them have protective spines, thorns, or other sharp components. How come?
What gives is evolution. Specifically, a process of development known as “convergent evolution,” in which essentially unrelated species that face comparable environments over time develop similar coping mechanisms.
In addition to their fatty, armored portions, these plants all share the fact that the majority of them evolved in dry environments. Long dry spells are more likely to be survived by plants that can store as much water as they can in their stems, leaves, and roots.
Additionally, you must maintain the water that has already been stored in your tissues. The fact that there are creatures scurrying about who would love to steal your water by devouring those succulent plant portions will be one of your major problems. You will be able to reproduce if you can stop those hungry and thirsty animals in any way possible.
In other words, a tried-and-true method for surviving arid climates is to become an armored succulent. It is hardly unexpected that many unrelated plants have adopted that tactic.
Consider which plant component is which as one strategy. Aloes, agaves, yuccas, and many other garden succulents have modified leaves as their succulent sections. Most of the time, the parts of cactus succulents are modified stems. The majority of cacti lack leaves, and those that do can be quickly distinguished as such because they are little, transient green objects that sprout laterally from succulent stalks.
Although the pads of prickly pears are frequently referred to as “leaves,” they hardly ever develop further leaves. Those modified stems are those flat pads. Jade plants, for example, have anatomy similar to other trees and shrubs, but they are thicker. Leaf succulents, on the other hand, typically have leaves that grow in spirally rosettes, like yuccas, aloes, and agaves. It’s almost probably not a cactus if you locate a plant with a rosette of structures that resemble they might have developed from leaves.
There is a cute kind of cactus called Leuchtenbergia principis that has extended non-leaf stem lumps called “tubercles” and can resemble a rosette leaf succulent. This is almost definitely true, but it is not a given. simply to keep things complex.
Observing where the spines are developing is the simplest and most accurate technique to determine whether something is a cactus. The modified leaves that make up cactus spines all originate from a specific “organ” called an areole that is only found in cacti. Every spine you see on a cactus will be growing out of an areole, which is a little patch that is typically elevated and has a woolly or hairy appearance (but don’t touch it to be sure). Only cacti have areoles, which can occasionally be difficult to spot because of wear from the weather but can still be seen if you know what to look for.
Even euphorbias that resemble cactus won’t be able to trick you once you know what an areole looks like. it is advantageous. In the desert, there are many spiky plants, and you don’t want to accidentally curse the incorrect one.