The Winter Hardy Cactus Garden
In a cooperative effort between the Central Ohio Cactus and Succulent Society and the Franklin Park Conservatory, the Winter Hardy Cactus Garden (once located in the courtyard of the Conservatory) was planted in May of 1998. The collection highlighted those species of cactus which have demonstrated both exceptional cold hardiness and tolerance to Ohio's high annual rainfall. The garden was planted in a very gravely and sandy soil to provide excellent drainage, and the courtyard setting provided a degree of protection from winter winds, and may also have provide a somewhat warmer microclimate which may moderate the extremes of winter temperatures; otherwise these plants received no protection from from the elements throughout the year. All of these plants have survived temperatures to below 0 degrees Fahrenheit, and some of these species are known to survive temperatures to below -30 degrees in habitat.
This garden was established to both expand the Conservatory's collection of cacti and other succulent plants, and to illustrate an extreme form of xeriscaping (gardening with plants which require minimal supplemental water during periods of drought).
On average, the garden included approximately 30 recognized species and varieties of cacti, from 5 different genera. Plants were chosen on their ability to survive Ohio's climate, and to illustrate the diversity of growth habits, size, flower colors and other traits of the hardy species (there may be in excess of 100 species, varieties and forms of cactus which are hardy to Central Ohio). All of the plants in the collection originated from the United States and Canada, but there are indications that a few species originating from colder regions of southern Argentina in South America may also prove to be hardy here. The collection included a plant of the "Eastern Prickly Pear" (Opuntia compressa) which was grown from a cutting taken from one of Ohio's few remaining wild populations of this species (it is Ohio's only native species of cactus), and also included several species which are threatened or endangered in habitat.
This was a test garden to assist in determining the cold and moisture tolerances of many different cactus species; the collection continually evolved over the years as new plants were tested. Occasionally plants were lost as a result of severe weather or other circumstances, and occasionally plants were removed to make room for additional species. Because growing space was limited, the collection comprised mostly of the small growing species.
Sadly, the winter hardy cactus garden ended its tenure at the Conservatory at the end of 2009, At present, the space is being use to highlight a selection of hardy carnivorous plants, and has also served as a demonstration butterfly garden. Perhaps in years to come, the Society will have an opportunity to establish another winter hardy cactus bed either on the Conservatory grounds, or at another location in the area. In the meantime, several of our members continue to grow winter hardy cacti in their own gardens, and will occasionally offer cuttings and seedlings at our annual show and sale
Among the species planted in the courtyard garden were:
Cylindropuntia imbricata, the "Cane Cholla", is a tall growing species, it can grow to perhaps 6 feet tall in northern gardens - but in habitat, I have seen specimens in excess of 8 feet tall, and others have reported plants in excess of 10 feet tall near Big Bend National Park. The species is quite variable, plants from more northern portions of its distribution will tend to be shorter, and more shrubby. The flowers are quite showy, and are typically a deep magenta to purple coloration, but this is quite variable - some populations have pure white flowers (variety alba, or albiflora), and others may have less showy flowers, with colors that approach brown in some individuals. Plants must be mature before they even begin to produce their first flowers. Some growers report that they grew their plants 10 years before they produced their first flowers; thereafter, they typically produced an annual display. While I have grown this species for many years, one of our members has grown this plant longer than I have - over 20 years here in central Ohio. The species and its varieties has a huge distribution through portions of Texas, Oklahoma, New Mexico, Arizona, Colorado, and even the southwestern corner of Kansas. It is very hardy, surviving temperatures to at least -25 degrees Fahrenheit here in Central Ohio. Other growers report that their plants have survived temperatures to -30 and even -40 degrees.
Cylindropuntia kleiniae, the "Candelabra Cholla" a tall growing species which quickly grows to heights in excess of 5 feet. I have grown a single clone of this species for nearly 20 years. It has survived temperatures down to below -20 degrees Fahrenheit, but seems to be at its limits here in central Ohio, for when I have sent cuttings to other growers in slightly cooler regions, (cooler portions of a USDA zone 5) it failed. Where it is happy, growth is rapid - established plants can add an additional 2 or more feet to each of its main branches each year. Growth is limited to about 5 feet tall here - even in protected areas, as heavy snows, freezing rain, and strong winds will tend to break branches when they grow much above 4 feet. In habitat ( the Chihuahuan Desert from central Mexico north into southern New Mexico, Texas, Arizona and into southwestern Oklahoma), where winters may be considerably less harsh, with generally less snow and ice, this plant can grow as tall as 9 feet. The flowers are small, to about 1.25 inches across and are of a curious wine-stained reddish-purple coloration on my plant. As in many of the cholla species, it may take many years before this plant matures sufficiently before blooming its first time, but will usually flower every year thereafter.
Cylindropuntia leptocaulis, the "Pencil Cholla", or "Desert Christmas Cactus": In its native habitat, this plant tends to grow in dense thickets, and can become quite a pest. Individual plants are relatively short shrubs growing from about 3 to 5 feet tall. The stems are quite thin, to about the diameter a pencil on new growth, although the main stem will become quite woody with time, enlarging to about 1.5 inches in diameter. It is a very variable species, but typically has long (1 to 2 inch) stout spines along its stems - some clones have shorter, more bristly spines, and a few are virtually spineless. I have grown several clones of this plant here in Columbus for a number of years, but it has always proven to be near its very limits of survival here. In all winters there is always at least some tip damage to the stems, and frequently, the stems are very nearly killed back to the ground, In extreme winters, the main plant is killed entirely, with only a few of the fallen bits of side branches surviving on the ground to establish new plants. In the protection of the Courtyard setting, this plant had finally managed to thrive. It grew against the foundation of the Conservatory in a very sunny site - I suspect that the sun heated the walls, and stray heat from the building helped to minimize the damaging effects of our cold winters. The plant at the Conservatory was the only plant of this species which I have seen in flower and fruit in Columbus, the flowers are smallish, and are typically of a yellow to yellowish green coloration. The mass effect in thickets in the wild must be quite a sight, but is less impressive on a single plant. The smallish fruits ripen in fall to a bright crimson, and retain this color through the winter months, and well into the spring, adding winter color. The decorative fruits are frequently consumed by birds and other wildlife in its native habitat, but the birds of Columbus do not seem to be especially interested in the fruits of this plant. It is an interesting plant, but its habit of dropping small side branches which readily root in the ground to establish new plants makes it a potential weed in regions where it is less marginally hardy.
Cylindropuntia viridiflora, the "Green Flowered Cholla" is a shrubby plant growing to about 3 or 4 feet tall and to about 5 feet wide or so. It is believed to be a natural hybrid of between Cylindropuntia imbricata, and Cylindropuntia whipplei, and in many respects, it is intermediate between the two. In its overall appearance, it is reminiscent of C. whipplei, but varies in the details of its spination, tubercle size and shape, and most importantly, in its flowers, which are closer to those of C. imbricata in size and shape. Its flowers are of a very distinctive coloration, but contrary to its name, the petal colors are not really green, the outermost petals are greenish, or streaked in green on their outer side, but the colors of the inside petals are of a pinkish skin tone. The plants are reliably hardy to at least -20 degrees Fahrenheit, and many growers report that their plants have survived temperatures to -30 degrees. I have found it to be susceptible to fungal infections, and have not been able to maintain this plant in my garden for more than a few years before it succumbs to the so-called "Black Death", but many other growers are able to grow this plant without any difficulty. There continues to be some question about its taxonomy: most authorities either regard it as a variety of Cylindropuntia imbricata, while others treat it as a hybrid, naming it Cylindropuntia X viridiflora. I nevertheless tend to use the name that was most commonly used back in the day when I first became interested in growing hardy cacti: Cylindropuntia viridiflora. Issues of taxonomy aside, this plant has a very restricted range, and is known only from two locations, (with a third population in dispute). Both of the two accepted locations are very restricted; there are possibly more plants in cultivation than there are in the wild - in my humble opinion, this plant should be given protection under the endangered species act - but since it is believed to be of a hybrid origin, it is not regarded as a true species, and therefore receives no protection whatsoever. This is an interesting plant, and deserves to be more widely grown.
Cylindropuntia whipplei, the "Rat Tail Cholla". This is a wide ranging species, with populations in Arizona, New Mexico, and Colorado. It is typically a low and shrubby plant, growing to between 6 inches to 2 feet tall and 3 to 4 feet wide in most populations, but with some individuals growing tall - reputedly to 6 feet tall in a few populations. There are also a number of clones which creep along the ground, growing several feet wide, but only a few inches tall. The stems are typically thin, to about 3/4 of an inch in diameter, but usually closer to half that width. The flowers are small, to about 1.25 inches across, and are yellow to greenish yellow in coloration, but as with all chollas, this plant may grow for many years here in Ohio without ever flowering. This species has the distinction of being the northernmost species of cholla, and is reputedly one of the most cold hardy species as well, with reports that it can survive temperatures down to -40 degrees Fahrenheit. The smaller, creeping clones are well suited to small garden spaces, and can also be grown in tubs, and large planters, the taller growing clones are best suited to open beds. Although it can easily tolerate our coldest winters, I have found this species to be especially prone to attacks of the so-called "Black Death" fungal infection which can quickly devastate this plant. While other growers have little difficulty in maintaining this plant, I have not been able to maintain it here for more than a few years before it it succumbs to fungal infection. It fared much better in the Conservatory setting, growing here a number of years until the hardy cactus bed was retired.
Grusonia clavata, the "Dagger Cholla" is a short plant growing to barely 6 inches tall (and usually shorter), but spreading in mats to 6 feet (or more) in diameter. The stems grow upright, and are club shaped to egg shaped; in some individuals, the stems can grow to as large as the size of a very small hens egg, but in most of the plants which I have seen, the stems are generally smaller, from about 1 to nearly 2 inches long, and about ½ to 1 inch in diameter.
The most distinctive feature of this species are its greatly flattened dagger-like spines which can measure from ½ to 1¼ inch in length. The main spines emerge a pinkish color, but are white when mature. The flowers are small, to about 2 inches in diameter and slightly less in length, and are yellow. The fruits measure from 1¼ to 2 inches in length and to one inch thick, and mature to a light yellow.
This is a slow grower in our climate, with most growth completed by mid summer: seed raised plants require at least three years of growth to attain a spread of six inches. Like its relatives, Grusonia clavata may require a number of years of growth before it will produce flowers; in four years from seed mine have not yet bloomed. It may be possible that the climate of Ohio makes it difficult for this species to initiate flower buds, but I imagine that in time, when my plants have achieved sufficient maturity, that they will bloom annually.
Grusonia clavata originates from central New Mexico, with additional populations in portions of northwestern New Mexico. It is quite tolerant of extreme cold (mine have survived temperatures to -24E Fahrenheit), but it is not so tolerant of extended periods of wet conditions, and should be given a very porous medium, and as much direct sun as can be provided. It also seems to grow best when daytime temperatures are hot and night temperatures are comparatively low. My plants seem to grow best when the relative humidity is low (or at least, low for Ohio) and it probably also benefits from good air circulation as well.
The small size, compact growth habit, and slow growth rate of this species makes it a suitable plant for growing in containers. Unlike some of the smaller Opuntias (O. fragilis and O. pusilla for example) the stems of Grusonia clavata are strongly attached to one another, and the plant does not periodically "fall to pieces."
Opuntia arenaria, The "Sand Prickly Pear". This species typically forms short dense clumps to about 6 inches high and reputedly spreading to as much as 9 feet in diameter (although it is easily maintained at a smaller size in cultivation). The pads are small, from about 1¼ - 4 inches long by ¾ - 2 inches wide, and are fairly thick, often to ¾ inch. While the pads are usually elongate to club shaped, occasionally pads are produced which are nearly cylindrical. These are weakly attached, and in conditions of cold weather or extended drought seem especially prone to break apart. The spines of Opuntia arenaria are fairly short, averaging about 1 inch in length, but the central spines may grow up to 2 inches, and are usually white, or brownish. The flowers are proportionately large, measuring from 2 to 2¾ inches in diameter, and are yellow, sometimes fading to a light pink.
This species is fairly unique in spreading by long rhizome-like structures. Roots and new clusters of pads may sprout along the length of these "rhizomes", which may travel up to 6 feet just under the surface of the soil.
Opuntia arenaria is native to the sandy banks and valleys along a short section of the Rio Grande River south of Las Cruces, New Mexico and into Texas near El Paso and south into Mexico. Despite its restricted, and specialized habitat (it only occurs on stabilized sand dunes or "sandhills") as well as its occurrence in fairly warm winter areas, this is a surprisingly hardy species here; my plants having survived several occurrences of temperatures to below -20E Fahrenheit.
Grown in central Ohio, the growth of this species can be quite prolific; in some years, my plants have produced new pads throughout the summer months or in several distinct waves over the course of the summer, with one plant increasing from a few pads to nearly fifty in a single season. In our average winters, my plants have survived without damage, but in our most severe winters, with temperatures below -20E Fahrenheit, or in severe ice-storms, my plants have shown considerable dieback, but I have never completely lost any of my plants, and these have always recovered rapidly. Opuntia arenaria is classified as a threatened species, and should be grown and distributed to preserve its genetic diversity, as urban sprawl, especially in and about El Paso, is decimating existing populations. This species makes an attractive and compact plant as well, suitable for small beds and containers.
Opuntia compressa, Opuntia humifusa, the "Eastern Prickly Pear" is a low, spreading plant, often sprawling to 3 or more feet across, but growing no taller than the height of two pads (to about 9 inches). Plants from the Mississippi River Valley typically have pads which are smooth and glossy, but the variety(ies) which grows in the State of Ohio tend to have slightly raised areoles and somewhat dull green surfaces. The pads are rather small, ranging from about the size of a silver dollar to larger forms with pads to as much as 5 inches long and about 2½ to 3 inches wide. The pads become remarkably wrinkled in autumn, and become quite prostrate. In spring, these pads root wherever they come into contact with the ground. Typically, old pads retain some trace of the wrinkling from the previous winter. Many populations are virtually spineless, although some forms may produce from 1 to 3 spines per areole, usually only produced on the areoles along the upper edge of the pads. The spines are fairly short, to about 1 inch in length and are usually a light grey or whitish to brownish in color.
Opuntia compressa is a reliable bloomer, producing a succession of flowers which are yellow or yellow with reddish centers, with each bloom measuring up to about 4 inches across (in variety grandiflora), although in most forms, the flowers are from 2 to 3 inches across.
This widespread species occurs in virtually every state east of the Mississippi River (except for the states of Maine, New Hampshire, and Vermont) and is widespread in many states west of the Mississippi as well. This is the only species of cactus known to be native to Ohio. Opuntia compressa is the species which seems best adapted to our climate, being both resistant to our cold winters, and high rainfall. It requires no unusual measures to grow it besides well drained, ordinary garden soil, and a site which is sunny. Many people grow it here without amending their soil with sand and gravel.
Throughout the greater portion of Opuntia compressa’s northeastern range, it is the only species of cactus present, and so identification is easy. It is nevertheless a highly variable species with a number of regional forms and varieties. The Ohio State University Herbarium preserves plants from a number of Ohio sites. The populations originating from the eastern portions of the Lake Erie shoreline are rather uniform, with plants with small (about 3 inch) nearly circular pads with the occasional spine produced on the areoles of the uppermost edges of the pad. Populations from other regions of the state are more variable, with typically larger pads which tend to be more oval shaped. The plants from the greater portion of Ohio vary widely in their spination, with many populations being virtually spineless, while others tend to produce more spines, usually only on the uppermost areoles, but in one collection, one spine was produced on nearly every areole on the edge of the pads. Whether these plants merely represent the normal range of traits to be found within this species, or if these traits are representative of several distinct forms and varieties is largely a matter of conjecture at this point, as many of the Ohio populations appear to have been eradicated, and are no longer available for study. Widespread agricultural use of herbicides has probably eliminated the greater portion of the native populations of this species. Most of the remaining populations occur on rocky outcrops, or deposits of sand and gravel left by ancient lakes, seas and glaciers; these are sites which are generally unsuitable for farming. I suspect that this species was once more prevalent in this state, and was possibly quite common in Ohio’s prairie regions.
Opuntia cymochilla is a widespread plant of the grasslands: it is a low and creeping species growing to a height of about 8 inches and spreading to as much as 3 or 4 feet. Its pads are nearly round, somewhat egg shaped, or may occasionally be slightly wider than long. Pads are typically rather small, ranging in size from about 2½ to as much as 6 inches in length and to about 4 inches wide. The pads tend to be fairly thick, typically about ½ inch.
Flowers are typically a solid yellow with no reddish centers (although a few populations are known to produce flowers with dark centers). The flowers are about 3 inches across. The fruits ripen to a dull brownish color and are edible, having one of the more sweet and palatable fruits of the hardy Opuntias. Some people harvest the fruits to make jams and jellies.
This is a widespread plant, occurring from South Dakota (it is said to be the most prevalent cactus of the Black Hills), south into northern Texas and west into New Mexico east of the Continental Divide, and into eastern Colorado, and South Wyoming.
Opuntia cymochila is remarkably cold hardy, many forms surviving temperatures to below -35E Fahrenheit with minimal damage. It seems to be quite moisture tolerant as well, and may tolerate conditions where Opuntia compressa and its varieties thrive without amending the soil with gravel and sand to improve its porosity.
Opuntia fragilis, the "Brittle Prickly Pear" is a small species which typically grows in dense mats to as much two feet wide and from 4 to as much as 8 inches tall. The stems are usually quite small, with the pads of some plants averaging about the size of a marble, to plants with pads to as much as 2½ inches long and nearly as wide or sometimes slightly wider. The pads are quite thick, and in some plants, they are very nearly circular in cross section, with minimal flattening. The stems are loosely attached to one another, accounting for both the common name and the specific epithet of this species.
The spines are fairly stout, and are strongly barbed. Some populations of this species are nearly spineless and are commonly sold as O. fragilis "variety" denudata (the varietal name is probably best regarded as a cultivar), or incorrectly under the name of "Opuntia inermis".
The flowers are large in comparison to the size of the pads, measuring to just under 2 inches in diameter, and are typically light yellow, or yellow with orange or reddish centers, or occasionally with light yellowish or greenish centers. Some plants (reputedly hybrids) are known to produce magenta flowers.
This is possibly the most cold hardy cactus of all as it is the most northerly species of cactus known. It occurs nearly to the arctic circle in the provinces of British Columbia and Alberta, Canada, and as far east as the upper peninsula of Michigan and southwestern Ontario, its western distribution extends to the drier islands and shores of Puget Sound and is reputed to extend to the southernmost islands of Alaska, although no recent searches have located these Alaskan populations. The southern extent of its range includes the northern portions of Arizona, New Mexico and the northern panhandle of Texas.
It has been suggested that the migrations of the American Bison which once shared greater portions of this species range may account for the remarkably wide distribution of Opuntia fragilis. Migrating Bison may have snagged pads, which clung to the fur of their legs and were carried great distances before the pads finally were worked loose. If the pads fell on suitable ground, they could root and ultimately establish new colonies.
Opuntia fragilis is adapted to dry grasslands and sagebrush deserts, preferring a sandy, gravely or rocky soil. In cultivation, this species should be given a very porous soil, containing extra drainage material such as sand and gravel, as it is fairly moisture sensitive, particularly during the winter months, otherwise it is a remarkably hardy species, with some clones easily surviving temperatures to -40E Fahrenheit. Its small size and compact growth makes this species suitable for small beds and container growing. It should be grown where it will not be disturbed, as the pads are quite easily detached; pets, wildlife and people may inadvertently carry off any pads which are not firmly rooted.
Opuntia sanguinocula is a robust plant, producing fairly large pads (usually from 6 to 8 inches long, but sometimes to as much as a foot long, and usually to about b as wide). All areoles produce large tufts of reddish brown glochids, which increase in size and number with age. Spines are produced on the uppermost areoles of the pad and on the edge of the pads. The spines are rather short, averaging about an inch or slightly longer. Typically, the spines are slender, with only a few produced per areole, and are generally yellowish or light brown when they emerge, but usually fade to whitish or light grey. In the plants which I have grown, new pads are usually produced at the side of the pad rather than from the upper portions of the stem, keeping the growth of this plant low and spreading. In the winter, pads become flaccid, flopping onto the ground, and wrinkling slightly, rooting wherever they come into contact with the ground.
The flowers of this species are large, often from 3 to 4 inches in diameter, with the flowers opening widely. The flowers are typically yellow, and may or may not have orange or reddish centers.
This is another very reliably hardy species, easily tolerating Ohio's winter temperatures; it seems to be very tolerant of our high rainfall as well. Once established, its growth rate can be rapid, with each stem adding an additional foot each year. The relatively large, and nearly round pads of this species matches many person's impressions of the prickly pears of the warmer regions of the American southwest, and better conveys an "western" cactus bed than many of the smaller padded prickly pears. Being a large and fast growing plant, it is best planted in a larger bed, and is generally unsuitable as a container plant. The large, fleshy fruits (once the glochids, skin, and seeds have been removed) are edible and are suitable for jams and jellies being both sweet and a bit tart.
Opuntia phaeacantha, the "New Mexico Prickly Pear" is a larger growing species with generally larger pads, measuring from 4 to 8 inches in length, and 3 to 7 inches in width. The plants are ascending and spreading. Some plants are said to grow heights of 3 feet, but in most forms, the plants are lower and more spreading, with the edges of the pads resting on the ground, growing to heights of about 18 inches or usually less. Plants may spread to as much as 8 feet, but can be maintained at a somewhat smaller size by judicious pruning.
The flowers of this species are from 2 to 3 inches in diameter, and the color can be variable, but in most populations, they are yellow to orange with red centers. Some plants (usually originating from Utah) may have bright red flowers.
This is a widespread species, occurring in western Texas and Oklahoma, virtually all of New Mexico, much of Arizona, the southern and eastern portions of Utah, and Colorado. Some authorities also include Nebraska and Montana in this specie's distribution.
I have found this to be a very hardy and adaptable species, readily surviving our coldest winters. In my garden, this species has survived temperatures to -24E Fahrenheit without damage, and would probably endure temperatures to -35E. It also seems to be quite moisture tolerant as well, being nearly as adaptable to high rainfall as Opuntia compressa and its varieties. This species is an aggressive grower and is not generally suited to small spaces or growing in containers.
Opuntia polyacantha, the "Plains Prickly Pear" or "Starvation Cactus" typically forms low spreading mats, with most forms seldom exceeding about 6 inches in height, and usually spreading several feet in diameter; in some very old plants, the mats may spread up to several yards. In most forms, the pads are quite small, from 1½ to 5 inches in length, and from about 1½ to 4 inches wide; thickness can vary from about a to about 1 inch. In most varieties, nearly all areoles bear spines, usually with the longest spines produced on the uppermost areoles. Spine length can vary from ¼ to as long as about 3 inches.
The flowers of this species are remarkably variable, from nearly white in the cultivar "Crystal Tide" through yellow or yellow with reddish centers to orange, pink, magenta and nearly red; some cultivars are said to have greenish and even chartreuse flowers. The flowers measure from 2 to 3½ inches across and are up to 2½ inches tall.
Opuntia polyacantha and its varieties have a remarkably wide distribution, extending from western Texas to southern California and north into the Provinces of Alberta and Saskatchewan, Canada.
This species and its varieties are remarkably cold hardy plants, with some populations regularly enduring temperatures to below -35E Fahrenheit. In my experience, this species and its varieties are not as adaptable to our higher rainfall and wet winters, so all should be provided with a soil which is especially porous, and should be provided with additional coarse sand and gravel.
Opuntia polyacantha is quite variable in many of its attributes: It can be extremely spiny with long bristly spines to nearly spineless, and its blooms can range in color from nearly white to yellow, pink, magenta, and red. This species should be tried for the wide range of flower colors alone; also, the long spined varieties should be tried for the contrast they give to a planting of species which are less spiny. The more compact, small padded clones are suitable for growing in containers and small beds.
This species was named the "Starvation Cactus" because their dry fruits and spiny and fibrous pads were useless as emergency fodder for animals during periods of drought.
Opuntia tortispina is typically a low spreading plant, to less than a foot in height, and spreading several feet. The pads are a dark green and are somewhat smaller than those of O. phaeacantha, to about 5 inches in length and about 3 inches wide but are usually smaller, and of medium thickness (to about a inch). The stems have long spines, to nearly 3 inches in length.
The flowers are rather variable, but most plants produce yellow or orangish blooms with reddish centers, although plants with pink or magenta flowers are occasionally found in the trade.
This is a common species in the grasslands of the southwest, occurring from southern Nevada, central Utah and Colorado and southwest Kansas, and south to northern Coahulia, Chihuahua and northeastern Sonora. In the Mojave, it is restricted to isolated pockets of grasslands in the mountains where the rainfall is higher than in the surrounding desert.
In general, this species looks similar to a less robust plant of Opuntia phaeacantha, but with closer set areoles and typically more spines which are proportionately longer in tortispina, also the spines tend to be more flattened than in O. phaeacantha.
Echinocereus reichenbachii v baileyi
Echinocereus coccineus v gurneyi
Escobaria vivipara v radiosa
Escobaria missouriensis v caespitosus
Pediocactus simpsonii v minor
The Prickly Pears (Opuntia), and their close relatives the Chollas (Cylindropuntia), and Club Chollas (Grusonia), are amongst the easiest and most adaptable of of the hardy cacti, and while I have featured a few of these species here, a much more comprehensive treatment of these plants can be found at The Opuntioids of the United States, a site created by Joe Shaw and David Ferguson, featuring descriptions and numerous photographs of many species of the Opuntias and their relatives in the United States. While many of these species are not hardy plants when grown in Ohio, there are a good number of species which will prove to be hardy here. Habitat information is a good indicator of the cold hardiness of many species. Plants which are native to the Texas panhandle, Oklahoma, northern New Mexico, Colorado, and much of Utah for example, are generally good contenders for Ohio gardens, also plants which grow in alpine regions. Their site is an excellent resource, and should be checked to give you habitat information and a better impression of the general appearance of each "opuntioid" species.
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