Opuntia Blog

Armatocereus rauhii can be a tall cactus; the name means “armed” cereus. There are two recognized supspecies, “balsaensis” and “rauhii.” A. rauhii ssp. rauhii is the shorter of the two (up to about 20 ft in height) and A. rauhii ssp. balsaensis can reach 30 ft. A quick search of Google “Scholar” indicates that much of the published peer-reviewed literature is in Spanish. Perhaps this plant is not well known outide of South America. 

Armatocereus rauhii (with Espostoa lanata), photo by Craig Howe

Armatocereus (the genus) is found in Peru and Ecuador. A. rahuhii seems to be limited to northwestern Peru. The stems of Armatocerus are strongly segmented, and generally well armed.

Escobaria vivipara

I’m confused about the differences between Coryphantha and Escobaria. I think that, as explained to me by various sources, the differences are small and perhaps difficult to detect. I understand that Escobaria flowers have fringed tepals, whereas the tepals of Coryphantha lack such fringe, but I don’t know if this is a hard rule or a soft rule.

Daiv Freeman (at CactiGuide) reports  that,

“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.”

An article by Dicht and Luthy provides an examination of the thinking about Coryphantha, and how it differs from Mammillaria. I’ll probably have to spend more time growing the various plants in order to understand some of the subtleties. You can read more about Coryphantha/Escobaria in the Flora of North America. You can view photos of Coryphantha or Escobaria species at CactiGuide.

Coryphantha durangensis, photo from uknown source

I hope a reader can help me identify this cactus; I think it is a type of Mammillaria. I don’t usually buy unnamed cacti, but this one was on sale for about $1.50 at Home Depot, or Lowes, or a similar megastore. There were several cacti and I though I’d try some out for cold hardiness.

I bought the plants when night dipped to about 35 F, and I left them on my patio for weeks while the nights grew progressively colder. When temperatures dropped to 20 F, I checked the plants and they were fine. Then, I left them out when temperatures dropped to about 15 F, and finally to about 10 F. Two cacti died, and the one depicted here survived. I don’t think the temperature was really 10 F on the patio because it is a covered patio and because the little cactus plant was next to the house wall, but it got pretty cold.

Unidentified cactus

Neobuxbaumia scoparia, click on photo for original source information, photo by Daiv Freeman

I don’t know much about Neobuxbaumia, or how (in particular) members of the genus differ from other columnar cacti. There are 8-10 species of Neobuxbaumia and species in Pseudomitrocereus and Rooksbya have been folded into Neobuxbaumia by some authors.

At least some Neobuxbaumia are bat pollinated, and possibly all of them are. The flowers are generally large and held “outwards” so that bats may approach them. Also, some Neobuxbaumia, or all, open at night.

Neobuxbaumia are reported in Mexico and Peru, and probably places in-between. The photo at the left is from the CactiGuide Neobuxbaumia page, you can also find out more about Neobuxbaumia here.

Echinocactus horizonthalonius

These big (grapefruit-sized) cacti were growing in the Big Bend region of Texas. They are Echinocactus horizonthalonius, a western relative of the Texas horse crippler cactus (Echinocactus texensis). E. horizonthalonius is also a relative of the Mojave Desert E. polycephalus.

E. horizonthalonius typically grows in limestone-derived soils with very good drainage.

Many forms of this cactus are hardy to USDA climate zone 6, but they resent over watering. E. horizonthalonius is common enough in far West Texas and south-central New Mexico.

Coryphanthus echinus, photographed in Big Bend region, Texas

Coryphanthus echinus is a globular cactus that seldom offsets; it has bright yellow flowers. Some plants may have areoles with a porrect central spine, whereas other areoles lack such a spine. The plants are generally easy to grow and have a reputation of being cold hardy (to USDA climate zone 6).

You can read more about C. echinus here. You can purchase C. echinus from High Country Gardens.

Ariocarpus fissuratus, photo by Craig Howe

Parts of Texas are home to Ariocarpus fissuratus, a plant wonderfully adapted to harsh conditions. Its gray-green (or brownish) color help it hide among rocks where it grows (typically in calcareous soils). Much of the plant is, in fact, underground as a subterranean storage organ–a factor that also helps Ariocarpus to hide.

Ariocarpus has been placed in various genera over the years, including:  Mammillaria, Anhalonium, and Roseocactus.  You can read more about A. fissuratus here and here.

Carnegiea gigantea

There is only one member of the genus Carnegiea, C. gigantea (the saguaro cactus). It is widely recognized around the world as a symbol of the American West, though it also occurs in Mexico. In the United States the plant is essentially found only in Arizona even though it calls to mind the whole West.

C. gigantea can reach 50 foot-tall, but individuals are often shorter than that. The ribs of the cactus provide an accordion-like architectural feature to the plant and also allow it to expand in size. The plant may expand when it absorbs water after a rain.  The trumpet-shaped flowers are white on the inside, but the floral tube is green on the exterior. The flowers are pollinated by bats. The edible fruit has been used to make wine and jams.

C. gigantea may be distantly related to Neobuxbaumia and Pachycereus; the three genera produce similar alkaloids.

You can read more about C. gigantea here, and here. You can purchase seeds or small plants of C. gigantean from Mesa Garden Nursery.

Aztekium hintonii

There are just two species of Aztekium, A. hintonii and A. ritteri. They are small, globular plants with pink or white-pink flowers. The two species grow on gypsum cliffs in Mexico and are quite limited in natural occurrence. Each species is known from its own (single) location in the state of Nuevo Leon.

Boedeker reported A. ritteri in 1928 and it was over 62 years later that A. hintonii was reported. Both plants are fairly small, and with limited occurrence. It is understandable that they were not discovered early in cactus discoveries.

You can read more about Aztekum here and here.

Copiapoa bridgesii, photo by Daiv Freeman at CactiGuide, click photo for original CactiGuide Web page

Copiapoa comprises a genus of 2 dozen (or perhaps 30) species of cacti from central and northern coastal Chile. Presumably, in such places, their water is from coastal fog or winter rains (or both).

The genus was originally described as “Echinocactus,” but Copiapoa was proposed in the 1920s. Copiapoa generally have yellow flowers and may be spiny, or not spiny. They have much variation within the genus.

The Copiapoa Handbook describes the genus in detail, providing maps and cultural information. I understand the book is sold out, but you might be able to find copies in bookstores or on Ebay. You can learn more about Copiapoa here, and here.

Guilded Flicker at nest in saguaro cactus

The Guilded Flicker is found in various habitats, but it is a famous woodpecker in the Sonoran Desert where it excavates nests in saguaro cacti. This flicker is different from the Red-shafted Flicker, the Northern Flicker, and the Yellow-shafted Flicker. The Guilded Flicker eats ants, berries, and saguaro fruit.

You can read more about the Guilded Flicker here, and here. You can learn more about the saguaro catus here.

Lobivia species, under lights, from Miles' to Go

I’ve ordered plants off and on from Miles (Miles’ to Go Nursery) in Arizona for over 10 years. The plants always come quickly and always arrive in very good shape. Additionally, most of the plants are of blooming size if they bloom while in a small pot.

Miles must get his plants in and keep them a while because he’ll advertize a plant as 3-inches and it will arrive and be nearly 4-inches across or tall. The plants are not expensive, typically $4.50 to $6 for the things I might order (Gymnocalycium, Lobivia, Rebutia, etc.).

Miles offers some cold-hardy plants but he doesn’t feature them as especially cold hardy. For instance, he sells several types of Gymnocalycium that will surely survive 10 F, but he doesn’t mention the fact. Similarly, he sells a variety of cold-tolerant Coryphantha, Escobaria, Echinocereus, etc. In fact, Miles sells many genera but few or no Opuntia.

Echinocactus polycephalus, Mojave Desert near Las Vegas, NV

Many cacti flower early in the Mojave Desert, but Echinocatus polycephalus blooms late, sometimes as late as the end of July. The blooms are pretty, and yellow, but not large and showy. “Polycephalus” means “many heads,” and, sure enough, E. polycephalus has many short stems that form “heads.”

E. polycephalus is not hard to find in rocky or gravelly areas of the Mojave Desert (2,500 to 4,000 ft), but it is seldom seen in cultivation. Perhaps one reason it is seldom seen is that it is not a fast grower. Another reason it might not be seen is that plants seldom, if ever, transplant successfully from the wild, and despite the damage it may cause some folks still collect cacti in the wild.

E. polcephalus grows from seed easily enough, but it resents overwatering. If you are lucky enough to have this plant it can probably tolerate 10 F, or perhaps a bit more cold (especially if the next day warms up).

You can read more about E. polycephalus here and here.

Lophophora

It is confusing to sort out Lophophora names; some authorities suggest there is really only one species, whereas others indicate there are four. Of course, the various putative species have have been named more than once.

The plants are small and slow growing, taking 20 years or more to reach adult size (about a small tangerine) in the wild. L. williamsii is the famous member of the group because it naturally contains mescaline–a mind altering hallucinogen. L. williamsii is well known as “peyote.”

Peyote plants are hunted by people and resold because of their hallucinogenic properties, and several sources report they are in danger of extinction in the wild. However, a simple Internet search suggests that there are multiple seed vendors around the world.

Lophophora might be an easy plant to grow (I’m without first-hand experience) because it comes from south Texas and north Mexico, in an area with sweltering hot summers and way-too-much winter rain (and sometimes summer rain). Cacti from this region, that I have grown, are flexible in their requirements; they are not so cranky as plants from drier (ie, more westerly) areas.

You can learn more about Lophophora here or here.

Monstrose Lophocereus schottii

Monstrose plants are not limited to cacti, but because of their normally limited morphology, monstrose cacti seem more remarkable and beautiful. The precise cause (or causes) of monstrose growth are unknown, but the results are appreciated.

Many monstrose (or cristate) cacti are not as strong as their “normal” counterparts. Thus, they are slower growing and sometimes more tender to drought and cold. However, the Lophocereus pictured here seems robust and happy.

You can learn more about monstrose plants here and here.

Espostoa lanata, in habitat, photo by Craig Howe

Espostoa lanata is a columnar cactus with “lanate” stems. Lanate is another word for downy or hairy. Mature plants form a cephalium on one side of the stem; thus, they bloom only from the cephalium and only at night. The fuzzy-hairy nature of the stems accounts for the common name of the cactus, “Peru old man.”

The plant in the image was photographed in habitat, in Peru, by Craig Howe. You can buy seeds or small plants of E. lanata from Mesa Garden. You can find more images of E. lanata on this page, and you can read about E. lanata here.

Lobivia arachnacantha, click on photo to see original Web page

Logee’s Greenhouse Web site says that Lobivia arachnacantha is good for a dry, neglected windowsill. Various Web information suggests that L. arachnacantha is a reliable bloomer, even as an indoor plant, if it gets some sun and overall good bright light. It is a good beginner plant and one bonus is that the flowers might be yellow, red, or orange.

The other name for this taxon is Echinopsis ancistrophora ssp. arachnacantha, but it has also been called Pseudolobivia arachnacantha.

You can buy the plant from Logee’s Greenhouse, or from Miles’ to Go Nursery. You can read more about L. aracnacantha here.

Haageocereus tenuis, click on image to see orginal large size, photo by Craig Howe

 They look like snakes wiggling around in sand, but the snake-like shapes are cacti. They are Haageocereus tenuis in Peru. They are clearly growing in a very dry area that doesn’t get much water, although recent rains have allowed a bit of green to grow.

You can learn more about Haageocereus tenuis here.

Cactus seedlings, click on image to see original photos (large size) at Flickr

Cacti are tough, and they can go months without water even in hot sun. Cacti are made to endure. But, it is a wonder how seedling cacti ever get started–they are tiny and dry out easily, and they don’t like hot sun.

For sure, many seeds germinate in the shade of their mother plant, or even in the shade of a shrub or a rock. The light is bright but not direct hot sun.

For water, it seems likely that most seedlings don’t germinate until there has been a fair bit of rain, and the soil is saturated with water. Even so it seems probable that most seedling cacti don’t make it, only those that germinate in “exceptional” years can survive. Exceptional years are those with extra rain and (perhaps) cooler temperatures. Some cactus might even need two exceptional years in a row.

However, that is not so unusual for plants that live many years. Cacti can survive for decades and if they only have “exceptional” years every 10 or 20 years then they’ll still have a chance for their seeds to germinate.

Trichocereus huascha in bloom, click on photo to see original image at Flikr

Some folks will tell you that Tricocereus plants are nothing more than columnar Echinopsis, and that they should not be termed Trichocereus. However, there is so much information out there that describes Trichocereus that I’m happy to use the older (if perhaps obsolete) term.

Trichocereus huascha has cylindrical stems and it branches from the base; thus the plant is often composed of several stems arising 6-24 inches from the ground. The flowers are glorious red and happy appearing. The plant is not a shy bloomer and is an easy plant to grow.

T. huascha is found in northern Argentina in highlands where it experiences a fair bit of cold weather. Yucca Do Nursery sells the plant and claims it is hardy to USDA climate zone 8b (15 F). Mesa Garden Nursery sells seeds of T. huascha that are reportedly hardy to 10 F. Likely the latter plants will survive to the upper single digits (7 or 8 F?) or perhaps colder.

Flowers are variable in T. huascha; they may be yellow, red, or orange. They are nice funnel-shaped flowers that are large.

You can learn more about Trichocereus here, and here.

Melocactus peruvianus with cephalium, photo by Craig Howe

Some cacti have juvenile and adult growth, two distinct forms. Only adult growth can flower. The adult growth forms a cephalium, a very distinct region of the shoot, or an entire portion of the shoot. The cephalium is the adult growth that can flower.

Melocactus peruvianus is on type of cactus that has juvenile and adult growth forms. The cephalium of M. peruvianus is distinctive and forms after years of juvenile growth.

“Cephalium is a, frequently brightly coloured, structure of wool and bristle at the growing tip of certain cacti. It is most commonly found on cacti of the genus Melocactus and can take a number of colours, forms and shapes.”

Cut cactus showing callus, click image to read original article

I found a nice article about cuttings on the WWW. It has great photos of callused cacti, of agave proliferations, and cactus cuttings. The article also describes how to grow cacti and succulents from seed, but it is the photos of the cutting process that interested me.

You can access the article (with color photos) here.

Sample graft from article

The World Wildlife Fund has prepared an interesting article that you can read here. It is concerned with “Trade and Conservation of Chihuahuan Desert Cacti. The article describes plants in Texas, New Mexico, Arizona, and Mexico that are vulnerable to overharvesting. Even Opuntia are vulnerable because they are harvested unsustainably for use in cosmetics.

Most of us, as cactus growers, only grow seed-grown plants from reliable dealers, but a blackmarket trade continues across international and state borders.

“World Wildlife Fund (WWF) considers the Chihuahuan Desert Ecoregion (CDE) of Mexico and the United States an important ecoregion for conservation because of its outstanding biological diversity, ecological fragility, and environmental concerns. The ecoregion, rich in natural resources, faces a range of visible threats stemming from human activities such as mining, fossil fuel exploration, livestock grazing, industrial agriculture, and development.”

Astrophytum asterius, 'Super Kabuto'

There are four species of Astrophytum; one of the most common is Bishop’s Cap (A. myriostigma). Another species common in cultivation is A. asterias.

Astrophytum asterias is a spotted species from Texas and Mexico (the Chihuahuan Desert) that resembles a sea urchin or sand dollar in 3D shape. A. asteras has given rise to some mutants. In some of the mutants the spots are enlarged and dramatic.

One spotted A. asterias mutant is ‘Super Kabuto.’ I’ve tried to understand what the spots are (are they regions where chlorophyll is just lacking, or regions of lenticels?), but I can’t figure out what the spots are. In the photo it is easy to see how the areoles (fuzzy) differ from the spots.

You can learn more about Astrophytum here and here. You can buy Astrophytum seeds at Mesa Garden Nursery.

Astrophytum myriostigma

Peacock in a cactus

I don’t recognize the cactus, but I do recognize the peacock. There was little information with the photo (click here for original), but I think the photo was taken in the Netherlands Antilles (Dutch Antilles/West Indies).

I’d be guessing, but I suppose the cactus is an introduced species (as is the peacock). You can learn more about peacocks here, and here. You can learn more about columnar cacti here.