Opuntia Blog

Yucca rostrata

Yucca rostrata is hardy to -20 F; it is hardy in Denver and can grow on the Atlantic seaboard. It takes many years to become a tall plant, but in time it can be 8- to 10-foot-tall. The trunk is crowned by a globe of blue-green leaves that are up to 2 inches wide and 2-foot-long. 

Y. rostrata can be a large plant in time, so give it good drainage and good space, and then stand back. ”Young plants are usually unbranched, but older plants may develop multiple heads near the top.”

You won’t find Opuntia martinina in many books, but it is described in Anderson’s book (The Cactus Family, 2001, Timber Press). Anderson describes it (page 507) as,

 ”…mostly sprawling but with somewhat ascending branches, to 60 cm high…Glochids yellow, tan, or brown. Spines borne on most or all of areoles, 1-8, mostly spreading, pale yellow with dull reddish brown bases, 2.5-4.5 cm (1-1.8 in) long…Distribution: northwestern Arizona.”

 In June this year I searched all around Kingman Arizona and found O. valida, O. gilvescens, O. dulcis, and other plants–in the thousands. I found only a single O. martiniana plant southwest of town. It was a small plant but imminently photographable. O. martiniana is a good looking plant, stately and with spines sticking straight out from the pads–it is very spiny.

Plants in the Kingman, AZ area can be expected to tolerate zero degrees Farenheit (0 F). O. martiniana should take a bit colder than that, perhaps -10 F because it was growing at about 5,000 ft.

Opuntia martiniana, Kingman, AZ

Delosperma nubigenum

I suspect there are more types, but I’ve come up with a list of 20 species and selections of Delosperma that are very hardy (to USDA climate zone 4).

Plant                                                    USDA Climate Zone

• Delosperma aberdeenense                               6
• Delosperma ashtonii                                        6
• Delosperma basuticum                                    5
• Delosperma brunnthaleri                                 6
• Delosperma congestum                                   4b/5
• Delosperma cooperi                                        5
• Delosperma deleeuwiae                                  5
• Delosperma dyeri                                            5
• Delosperma floribundum                                6
• Delosperma herbeum                                      6
• Delosperma nubigenum                                  4
• Delosperma sphalmantiodes                           5
• Delosperma sutherlandii                                 6
• Delosperma ‘Osberg’,                                     6                     
• Delosperma ‘Kelaidis’                                     6
• Delosperma ‘Beaufort West’                           6b
• Delosperma ‘Gold Nugget’                             5
• Delosperma ‘John Proffit’                               4/5
• Delosperma ‘Lavender Ice’                             4/5

Opuntia curospina

Opuntia curovspina is a handsome plant that distantly resembles O. chlorotica (even with spines on the central trunk); it is found in northwestern Arizona and adjacent Nevada and California. The plants are generally 2-foot-tall and make a handsome, symmetrical shrub. But, they may also sprawl a bit and be shorter or a bit taller. Exceptionally old specimens may reach 5-foot-tall.

O. curvospina is sometimes described as O. x curvispina, a proposed hybrid species arising from O. chlorotica and O. phaecantha. A hybrid origin may be possible, but the species is as constant and easily identified as any other large Opuntia. It is clearly not a product of recent hybridization: if recently derived, more variability and patchier distribution would be expected.

Given the location where it naturally occurs, O. curvospina probably tolerates cold to zero F, and may resent too much moisture.

Opuntia curvospina, north of Kingman, AZ

Austrocylindropuntia exaltata

At first look you might wonder if Austrocylindropuntia exaltata is related to Cylindropuntia imbricata, but these two opuntiads are not closely related. The first one is found in South America (in Peru and Chile) and the second one is found in North America.

A. exaltata has nice red flowers and can be found near the equator growing up to 10,000 ft elevation, or higher. C. imbricata has magenta flowers and grows from 1,000 ft to about 6,000 feet in Texas and New Mexico (and Mexico).

I’ve never grown A. exaltata, but C. imbricata is a bullet-tough plant that withstands cold, too much water, and searing heat. Both can be expected to take up a fair bit of space in the garden as the grow tall and semi-wide.

It is not hard to find Opuntia phaecantha in the American Southwest; the problem is that there are things that look like it that will confuse you. However, the good news is that almost any imposter is as hardy as O. phaecantha. Additionally, if planted with good drainage, O. phaeacantha and the similar plants will tolerate a fair bit of spring and summer rain.

O. phaecantha flowers are typically yellow, but they may have yellow centers. The imposters might be O. tortispina, O. dulcis, or perhaps O. gilvescens. Just plant them where they’ll get lots of sun and “stand back.”

Opuntia phaecantha, New Mexico

Opuntia pusilla, garden plant

Opuntia pusilla (some refer to it as O. drummondii) is found along the Atlantic Coast of the USA and the Gulf Coast panhandle of Florida. It has been reported from Texas but I’ve never seen it there (but there is a lot of coast to search).

In the sand dunes O. pusilla has a hard look, a desert look. In the garden, in rich soil and with frequent water, it grows like a weed and becomes rich green and luxuriant. A single cladode grows quickly to crowd over the sides of an 8-inch-diamater pot in a year or two. The cladodes easily break apart and soon different pots are growing their own O. pusilla. I wonder if O. pusilla is an invasive species in some habitats.

The spines are amazingly vicious, perhaps expected from a big cactus but not so from the “look” of O. pusilla. Perhaps part of their nastiness is that the plant grows a nice safe-looking spinach-green. Also, the spines seem straight and without guile, but actually they have a wonderful assortment of barbs that prevent dislodging.

The flowers of O. pusilla are small for an Opuntia, but they are cheerful enough. They are a nice canary yellow; I’ve never seen any with a hint of red or pink.

I don’t know the extent of O. pusilla cold hardiness, but they can be expected to take zero F easily, even with snow and rain. The plant also enjoys water, growing fast in the summer if it has lots of water.

Opuntia pusilla, click image for original Web site (southeasternplants.com)

Sheep and cattle can be fed Opuntia, especially new growth that has soft (or no) spines. Opuntia cladodes are not high in protein, and are usually supplemented with other food such as alfalfa or grain.

Interestingly, one paper (Cactus (Opuntia spp) as Forage, 2002, chapter by GC De Kock) reports that sheep can live up to 500 days without a water source, if they have sufficient Opuntia pads to eat.

One Web report claims that certain cattle are helping to save drylands because they eat the introduced prickly pear plants (possibly O. ficus-indica).

“Cows are playing an important role in land restoration in Baringo by eating up the invasive prickly pear cactus a nasty invasive plant that is destroying the drylands. It’s not obvious at all for cows to eat this thorny cactus, but Murry Roberts and his wife Elizabeth Meyerhoff told me about an amazing project that their organization, Rehabilitation of Arid Environments, has been working on. A few years ago they discovered that a local farmer had a bull that not only ate the nasty exotic thorny ugly, plant, but also taught other cows to go for it too.”

Graptopetalum is a common companion plant for cacti in areas where the temperature is mild (USDA zone 9a and warmer). G. paraguayense is typically hardy in frosts that don’t drop below 18-22 F, and which warm up quickly the next morning.

The plants are easy to grow–tolerating extreme drought, but also regular water. They are attractive with their blue-gray or purple-gray leaves arranged in rosettes on stems. The leaves fall off easily, but just as easily will root to form a new plant.

Graptopetalum paraguayense, image from Wikimedia

Craig Howe took a trip to Peru this past fall (2009), and he obtained some excellent photos of many different types of cacti in habitat. I’ve been working to put the images online along with Craig’s narrative.

The first few pages are done and you can find the images here. However, just remember that only the the first few pages are done. The other pages might be done, undone, half-done, or not even there. I’ll get the other pages ready in the next week or two and let you know when that is accomplished.

Update: January 9, 2010: All the images are now posted–enjoy them.

You can also find many of the same images at the CactiGuide.

Melocactus peruvianus in Peru

Opuntia bentonii with fruit

I’ve only seen Opuntia bentonii in Texas, and only in Texas within 40-50 miles of Houston. I’ve only seen O. bentonii growing along the coast, typically right on sand within sound of ocean waves.  In some ways O. bentonii looks like a short O. lindheimeri plant, with the yellow spines and the shape of the pads.

However, O. bentonii grows with O. lindheimeri on parts of Bolivar Peninsula (near Houston). O. lindheimeri is typically twice the height of O. bentonii, and O. lindheimeri grows back from the water, whereas O. bentonii tends to grow right up on the last dune before the waves. Additionally, O. bentonii has yellow stigmas whereas O. lindheimeri had green stigmas. Finally, O. bentonii has nearly spherical fruit, unlike the more elongate fruit of O. lindheimeri. 

O. bentonii was described in 1911, and then promptly forgotten. I think that everyone assumed any cactus with yellow spines was O. lindheimeri, which some seem to think is nothing more than a variety of O. engelmannii. But, O. bentonii is different from anything O. lindheimeri or O. engelmannii.

In cultivation the two plants are clearly different and easy to tell apart because O. bentonii has a “cleaner” look, a less rugged-spiny look. In the wild there are three main differences:

1. O. bentonii grows close to the water
2. O. bentonii is shorter
3. O. bentonii has semi-spherical fruit
4. O. bentonii has yellow stigmas

Growing along the ocean where there is little freezing cold weather, I’d be surprised if O. bentonii tolerated temperatures lower than 5 F or 10 F. But, it sure does tolerate salt water and lots of garden water.

Opuntia bentonii flower and buds

Opuntia flower with bee, notice stamens pressed against central stigma/style

Oligolectic bees are bees that prefer a narrow source of flowers. Thus, oligolectic bees that pollinate Opuntia flowers might fail to pollinate the flowers of adjacent plants, and vice versa.

Some Opuntia flowers are interesting because the stamens move inwards toward the pistol when an insect lands on the flower. Somehow the plant senses the insect, and the stamens bend towards the center of the flower. The result of such bending is that the inner stamens are covered by the outer stamens. The inner stamens are “buried” by the slightly longer outer stamens that bend over them. Notice the flower with the bee; you can clearly see that outer stamens “bury” inner stamens (right side of style) making it difficult for a bee to get to the pollen on the lower stamens.

All the bending and covering means that about 80% of the pollen in an Opuntia flower is hidden; it is covered over. Thus, most insects don’t find most of the pollen; insects must “dig” below the top layer of stamens to find the lower layer (the buried stamens). According to a paper published by Schlindwein and Wittmann (Plant Syst. Evol. vol 204, pages 179-193), only a few species of bees (out of the many possible types) actually burrow down to reach the “real” reward–the 80% of the pollen and nectar at the base of the stamens.

Therefore, some oligolectic bee species burrow for the riches, but the interesting thing is that such bee species are the ones that do most of the pollinating because all the digging and burrowing covers them in pollen and likely ensures that they transfer the most pollen to the stigmas of other flowers. The plant wins with such an arrangement, and the bee wins.

Small Opuntia whipplei, Kingman, AZ

Opuntia whipplei may make short plants (under a foot tall), or it may form plant over 4-foot-tall. The species has a lot of variation in size. Additionally, the species is found over a large range: from the southern tip of Nevada, across northern Arizona, all the way to northwestern New Mexico, and into adjacent portions of Utah and Colorado. It is a durable and easy-to-care-for plant, tolerating more water than many cacti.

O. whipplei is a Cylindropuntia, so it has longish, cylindrical cladodes, rather than the flat, pancake-like cladodes of “real” Opuntia. Hybrids between Opuntia whipplei and O. imbricata have been reported; these tend to have greenish-purple (or green) flowers. Additionally, O. whipplei is reported (by the Flora of North America) to hybridize with O. leptocaulis. The species and the hybrids are wonderfully hardy, easily taking -10 F, and perhaps colder.

It is reported that O. multigeniculata is a hybrid between O. whipplei and O. echinocarpa, but as near as I can tell, O. geniculata is now a “real” species no matter its origins.

Close-up of Opuntia whipplei cladode

Opuntia puberula, growing flat against the soil

Opuntia puberula has a nontypical habit of growth. Essentially all of the cladodes are horizontal with the surface of the soil. The plant mostly lays flat and grows near to the soil surface as may Opuntia polyacantha, but unlike O. polyacantha the cladodes are large (saucer-sized) and horizonal with the surface of the soil.

One study (by L. Sortibran and coworkers, Amer. J. Bot. 2005, vol 92, page 702) examined the effect of light upon the cladodes and found the plant was more horizontal (ie, flatter) in low light situations. The horizontal growth has the effect of making one side of the cladode face upwards into the light. Perhaps the strange growth habit helps the plant to better collect light in the shady conditions in which it grows underneath other shrubs.

” The horizontal position of O. puberula cladodes, which is anatomically determined, restricts it to shaded habitats, where the plants do not overheat…”

Opuntia in Madagascar, man holding fruit

The Web has much information, about many topics. One paper of interest is “Introduced Opuntia spp. in Southern Madagasgar: Problems and Opportunities.” The document if full of interesting facts, but the description of a famine caused by the collapse of Opuntia in the 1920s and 1930s is astonishing.

Opuntia species were introduced into Madagascar before the 19th Century. The earliest introduced species may have been O. monacantha or O. ficus-indica when French forces used the plants to create a living fence. Within a hundred years villages has adopted the use of cacti and the plants were widespread in southern Madagascar. It is presumed that wild animals and livestock (eating fruits) assisted in the spread of seeds. Eventually, infestations became a problem and some cultivated fields were abandoned because of Opuntia infestations.

Despite problems, the Opuntia were used in livestock production, sometimes helping by providing food in drought seasons. In 1923 the cochineal insect was introduced and Opuntia rapidly died off; this caused a huge problem as Opuntia-dependent livestock suffered from starvation. Loss of livestock resulted in a famine and tens of thousands of people died. Eventually, Opuntia were introduced that were resistant to the cochineal insect and Opuntia recovered as an important factor in the economy of southern Madagascar.

Opuntia monacantha, image from Wikimedia

Baboon feeding on Opuntia fruit, click image to access original Web page, photo by Dr. Shirley Strum

Opuntia stricta-like and Opuntia-dillenii-like plants have spread to Africa, Australia, and other parts of the globe. Many of them have become naturalized. The phenomenon is not an ancient fact; it is still happening. Each year new lands are colonized by Opuntia species of different types.

Dr. Strum (a professor at the University of California, San Diego) has been studying baboons in Kenya for some time. She reports that one Opuntia species has invaded one or two of her studies areas in the past years–she’s observed baboons eating the fruit (and elephants eating the fruit  too). Dr. Strum has studied how the Opuntia has spread, how animals interact with it. She reports that the plant has fruit much of the year, unlike other invasive Opuntia that seasonally bear fruit.

Her studies show us that desertification is a real problem around the world, and an ongoing problem. But, all is not bad. She reports that when the Opuntia invaded an area the people were able to make a juice that is served to tourists.

“When an invasive species of Opuntia cactus became a serious problem in the region (see History) UNBP helped the Twala women’s group develop a cocktail syrup from the fruit of the cactus, to market to tourists”

LINK:  Dr. Shirley Strum’s Web site (Uaso Ngiro Baboon Project in Kenya)

Opuntia that has invaded Dr. Strum's research areas, photo by Dr. Shirley Strum

Corona Cactus Nursery, mail order

Corona Cactus Nursery is located in Corona, CA, and has a nice, fast Web site. You can navigate though several important sections with a few clicks: Plant of the Month, Photo Gallery, and Cold-hardy Cacti. The Photo Gallery provides lots of images of plants in habitat as well as National Parks and other scenic views (eg, Huntington Botanical Gardens). One of my favorite images on the site shows a hillside of Saguaros with Opuntia. 

 The offering of cold-hardy plants is good, with over 10 cold-hardy Cylindropuntia species offered, over 30 cold-hardy Opuntia species, and dozens of ball and barrel cacti. In addition to cold-hardy plants Corona Cactus Nursery offers about 3 dozen genera of cacti in total (140 different species) and about that many species of succulents. They are increasing their stock and the next year or two will see many more plants offered.

There are clear instructions on the Web site for ordering, and details about shipping. Click on the prickly pear to go to the Corona Cactus Nursery.

Opuntia leptocaulis, photo by Gary Nored

Opuntia leptocaulis (Cylindropuntia leptocaulis) can be found from central Arizona, to southern Oklahoma, east almost to Houston, and south into Mexico. It is sometimes called the pencil cactus because its slim stems are thought to resemble pencils. Actually, the name “leptocaulis” means “butterfly stem,” referring to the thin abdomen of butterflies.

Sometimes long-spined and short-spined O. leptocaulis plants can be found growing side-by-side, as well as plants with silver or gold spines. Some plants have ripe red fruit in December, and the plant has been called the Christmas berry cactus. O. leptocaulis can form single short plants, or plants to nearly 5-foot-tall, or they can form thickets. They are easy going plants that tolerate too much water, and way too much cold (zone 5b?)–though much depends upon where the plant came from (Brownsville, TX, or southern OK).

Opuntia leptocaulis, east Texas

Ecinomastus johnsonii

Echinomastus johnsonii is commonly found in rocky and gravelly areas of the Mojave desert, as well as southwest Arizona. The plant is extremely spiny and the dry spines can look like wicker or twine; overall the little balls and barrels can resemble balls of brown twine. In spring, after rains, the spines acquire a glistening burgundy color. The plants have been observed on low rocky slopes of the mountains surrounding Las Vegas, NV.  

After several rains, at the beginning of spring, even in very hot and dry weather, the plants bloom. It is a startling sight to see the large purple or magenta flowers popping out of a dusty ball of string. Occasionally pink-flowered or yellow-flowered plants can be found, and plants may vary in spination.

Like so many cacti E. johnsonii is insect pollinated and the seeds are probably spread by birds. Small mammals may also spread the seeds, or destroy them through eating. The Flora of North America (online) provides a technical description of E. johnsonii.

E. johnsonii has been named different things by different botanists, including: Thelocactus johnsonii, Neolloydia johnsonii, and Ferocactus johnsonii. Y0u can see a great photo of the yellow-flowered E. johnsonii in the August 2008 issue (page 4) of the Central Spine (by Peter Breslin).

Sclerocactus wrightiae is an endangered species, listed in 1979 by the US Fish and Wildlife Service. It grows in a few counties in Utah, and nowhere else. Another name for the cactus is “fish hook” cactus, a name it richly deserves.  

 The plant is typically small, less than six  inches tall, and has white, yellow, or pink flowers. The species may exhibit variation from location to location (eg, flower color), perhaps due to introgression with other sclerocacti.

S. wrightiae  can be found in pinon juniper woodlands at 4,200 ft. to nearly 6,000 ft, often in association with grasses and Opuntia polyacantha. Typically, the plants are growing in very exposed (windy, sunny) locations and in alkaline soils.

Sclerocactus wrightiae, image from State of Utah Natural Resources

Cactus wren, image from Wikimedia

The cactus wren is found in the Mojave, Sonora, and Chihuahua Deserts; the wren may be found in southern California, Nevada, or Arizona, and deep into Mexico. The bird is easily observed flitting about the desert in search of insects, and its nests may be found in various large cacti including chollas (Cylindropuntia), saguaro (in holes), and some other columnar or barrel cacti. Or, sometimes the plant will nest in yucca plants.

 Males and females resemble each other, and both search for ants, beetles, grasshoppers, and bees, etc, though they might eat a bit of fruit now and then or seeds. The birds are remarkably efficient at extracting water from their prey, and they seldom need to drink. The white eye stripe and the black breast spots are useful for identification; there is no other bird like it.

I’ve seen this bird throughout the Mojave desert, but irregularly so. The nests are hard to miss, often a scramble of twigs (with a roof and “tunnel” entry) in a large cholla or perhaps a Joshua tree.

Cactus wren nest in Opuntia acanthodes, Kingman, AZ

North of Las Lajas, Nequen, Argentina

The southern part of Argentina is home to varieity of cacti, including opuntiads. Pterocactus, Austrocylindropuntia, and Maihueniopsis are all former members of the genus Opuntia. One nice Web site that shows plants and habitat photos is “Cacti from Neuquén, Argentina.”

The site discusses the plants that occur in the area, as well as the habitats that they are found in. The photos are not large but they are beautiful.

There are a number of Cylidropuntia species in Texas; they tend to be sturdy, tolerant of too much water, and cold-hardy. Opuntia davisii is found in western Texas and in eastern New Mexico. Curtis’s Botanical Magazine wrote in 1882 that O. davisii is:  

“A small shrubby species, remarkable for the bronzy color of the flowers, which have a peculiar metallic lustre…O. davisii is a native of the district of New Mexico, eastward and westward of the Tucamcari Hills…on the head waters of the Canadian River, a branch of the Arkansas.”

Opuntia davisii, photo from Gary Nored, click for original at Flickr

Wikipedia reports that:

Hecktia species or hybrid, image from Wikipedia

“Hechtia is a genus of the botanical family Bromeliaceae, subfamily Pitcairnioideae. The genus is named for Julius Gottfried Conrad Hecht, German counselor to the King of Prussia. The plants of this genus are [generally]  dioecious.”

The plants related to pineapple plants, which are also members of the Bromeliaceae. The plants are not particularly cold hardy, but H. texensis typically survived overnight frosts of 22 F in my Houston-area garden and never seemed to suffer. H. texensis is a species of north Mexico and west/south Texas (Big Bend region).

The plants appreciate excellent drainage and can be grown with cacti, but in a flower pot they will accept water for a longer period than many strictly desert cacti, even enduring the year-round rains of eastern Texas. Varieties with serrated leaves can be vicious but beautiful.