In game of natural selection, some cactus species have adapted so successfully that their natural habitat can extend across many hundreds of miles—several USA or Mexico states. Now in darkest winter, it’s time to talk about the “Snowball Cactus” which is just such a one: Mammillaria candida (Scheidweiler 1838). The spine covering on Mammillaria candida is so dense that the cactus does appear like a big snowball or puffball. The flowers can be light pink, dark pink, white with dark midveins… or even yellow!

Its habitat stretches across several states in northeastern Mexico: Coahuila, Nuevo León, San Luis Potosí, and Tamaulipas.

Mammillaria candida grown and photographed by Sentient Meat

Unlike some puffball-like mammillaria, Mammillaria candida has spines which really mean business. I thought it looked soft and friendly so I started to repot it without gloves. I thought if I moved slowly and gently I could just turn it upside down with one hand and rest it ever-so-lightly in my other hand. Big mistake! After trying this maneuver gingerly a couple times, I gave up. I can try again in the spring. With gloves.

Mammillaria candida (syn M. ortizrubiona) ML 656 - Photo : Michel Lacoste at Mammillarias.net

M candida is sometimes separated from the rest of Mammillaria into its own genus, Mammilloydia, because its seeds are not pitted and lack the perisperm found in all other mammillaria. Recent molecular studies, however, place M. candida squarely within Mammillaria, a huge genus which includes many cacti much more distantly related than Mammillaria candida.

Mammillaria candida - Photo : Willy at Mammillarias.net

See Also

Mammillarias.net gallery of species starting with C

Ortegocactus has an unusual, lumpy surface and distinctive, pale-green skin.

Ortegocactus, a genus with only one species: macdougallii

It’s not very scientific to sort plants by how interesting they look. After all, why should a plant’s place in science—the accidents of its evolution—also tickle our human sense of beauty? Why should a plant with scientific interest also match the desires of home growers of cacti and succulents?

Ortegocactus closeup. Note the furrows in the tubercle tops in this mature individual.

What does surprise me is how often plants which stick out in the science of plant naming—plants from a monospecific genus—are also interesting to look at.

Ortegocactus in habitat, photo by Amante Darmanin at cactuscristatemania.blogspot.com

A monospecific genus is a genus with only one species. Sometimes this is an isolated population with millions of years of adaptation to a particular evolutionary niche—long enough to diverge from other genera. In other cases, plants from a monospecific genus may be highly variable in size and shape (or habit) and may occur over a wide region. The physical differences between populations are simply too slight, too insignificant to warrant different species names (aka specific epithets).

Ortegocactus habitat. Photo by Amante Darmanin at CactusCristateMania.blogspot.com

Ortegocactus is a monospecific genus thought to be isolated for much of its recent evolution. In habitat, Ortegocactus macdougallii is known from one small area—the limestone scree and escarpments of a hill known as El Cántaro, 4km west of San José Lachiguiri, Oaxaca, Mexico.

The exact position of Ortegocactus in the cactus evolutionary tree has been debated. Recent molecular phylogenetic work by Butterworth places it close to genus Neolloydia and Cochemiea and to the series Ancistracanthae within the enormous genus Mammillaria, now seen to be polyphyletic.

The municipality of San José Lachiguiri lies between 16 ° 22' north latitude and 96 ° 21' west longitude at 1670 meters above sea level.

See Also

Ortegocactus at Desert-Tropicals.com

Ortegocactus at Cactus-Art.Biz

Ortegocactus at WelcomeToCactusLand.Com

Ortegocactus at CactusCristateMania.blogspot.com

San José Lachiguiri at the Encyclopedia of Mexico Municipalities, State of Oaxaca

Butterworth, Charles A. and Wallace, Robert S. 2004. Phylogenetic studies of Mammillaria (Cactaceae)—insights from chloroplast sequence variation and hypothesis testing using the parametric bootstrap. American Journal of Botany. 91:1086-1098.

Addendum: quote from Butterworth’s paper and commentary:

Clade A [a group which appears to have evolved from a single population] includes sampled members of the genera Coryphantha, Escobaria, and Pelecyphora, which form sister lineages to sampled taxa of Hunt’s and Lu ?thy’s series Ancistracanthae and subgenus Cochemiea, respectively, thus clearly demonstrating paraphyly within Mammillaria. Furthermore, within the core group of series Ancistracanthae sensu Hunt and subgenus Cochemiea sensu Lu ?thy, our phylogeny places Ortegocactus macdougallii and Neolloydiaconoidea. Discovered by MacDougall in the early 1950s and described by Alexander (1961), Ortegocactus macdougallii has been contentious in its placement in relation to other members of tribe Cacteae. Bravo-Hollis and Sanchez-Mejorada (1991) sank this genus into Neobesseya, members of which are now commonly accepted as species of Escobaria (Hunt, 1992, 1999; Barthlott and Hunt, 1993). Hunt and Taylor (1986, 1990) suggested that Ortegocactus may be referable to the genus Mammillaria, although an official transfer to Mammillaria was not made. Barthlott and Hunt (1993) also commented on the similarities of Ortegocactus and Mammillaria, going so far as to suggest that Ortegocactus is reminiscent of M. schumannii. Butterworth et al. (2002) also suggested that Ortegocactus shared a greater affinity with members of Mammillaria than with Escobaria or Coryphantha. The data presented in this paper do indeed show that O. macdougallii is embedded within members of Mammillaria, its closest Mammillaria relatives including M. schumannii. However, at present the transfer of Ortegocactus to Mammillaria would be inappropriate because of the polyphyletic nature of Mammillaria as seen in our analyses.

Translation: Ortegocactus appears to share the same lineage of many Mammillaria, so much so that its DNA (and the model we reconstruct from this DNA of Ortegocactus evolution) would justify calling it a Mammillaria… EXCEPT that other genera also have this same problem, too—Neolloydia, Cochemiea, some Coryphantha and Escobaria. They all seem to be closely embedded within the evolutionary tree of what we otherwise call Mammillaria. So it would be hasty to rename Ortegocactus until we figure out what to do with ALL these naming problems.

When I bought this Lobivia schieliana (syn Echinopsis schieliana), it had no flowers or buds. I got it for the wonderful spines, which turn the rounded (globose) stems of the plant into little inverted birds’ nests. It was a homely beauty, a miniature sculpture of meticulously attached pieces of straw spun into whorls. It was in fact a perfect example of a particular cactus aesthetic: curious, ugly-as-beautiful — the implicit danger of spines, tamed by culture… and in this case, by the plant’s tendency to use its defensive spines as horny shield rather than stabbing weapons.

And then… out of nowhere… the blooms. Shocking red, raised above the body of the plant on narrow tubes — the better to be seen by their dancing partners… hummingbirds? Much as I want to write about my other strange cacti — exquisite snowy globes or pineapples with spines like bouquets of grass — I can’t ignore these flowers any better than the hummingbirds can.

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PS One of the… I say THE… references on cactus just arrived in the mail and I’m very excited: The Cactus Family (2001) by Edward F. Anderson. He writes,

Echinopsis schieliana (Backeburg) D. R. Hunt 1987

Lobivia schieliana Backeberg 1957, L. backeburgii subsp. schieliana (Backeburg) G. D. Rowley 1982
Lobivia quiabayensis Rausch 1968, Echinopsis maximiliana subsp. quiabayensis (Rausch) G. D. Rowley 1982
Lobivia leptacantha Rausch 1972

Plants often forming clusters from basal branching. Stems globose to cylindrical, often slender, to 4.5 cm (1.8 in) long and 3.5 cm (1.4 in) in diameter. Ribs about 14. Central spine one, often absent at first, bent downward, light brown, 5–6 mm (0.2 in) long. Radial spines about 14, pectinate to radiating, interlacing, light brown. Flowers bright light red; floral tubes slender. Distribution: Peru and Bolivia.

Revisiting Mammillaria hernandezii in October, this time in bloom

On a recent Succulent Sunday we saw Mammillaria hernandezii. I wrote about its relatively large, purple-pink flowers, but since a picture is worth at least as many words as I wrote, here’s a follow-up. This was the first flower; if you look closely you can see the conical buds for more flowers to come. Also see how the smaller head has grown much larger in 3 months.

The same plant(s) from back in July. Besides the bloom, notice how much smaller the second head was.

In my yard, I tend to overlook Thelocactus bicolor until it blooms. Its body is green, moderately spiny and round — about 3 inches across in this particular young plant (globose… or actually ovoidal in this beautiful technical summary on Thelocactus). The problem is, hundreds or thousands of cacti fit a similar description, including dozens under my care.

When it does bloom, “The Glory of Texas” is impossible to ignore. From a distance the bright magenta petals catch your eye (faded to pink here by my cheap camera). Something about the deep crimson center and glistening yellow pollen also jumps out at you, even from 10 yards away… not to mention the bloom’s size: on the young plant pictured, the flower is an inch wider than the entire body of of the plant.

Thelocactus bicolor is widespread in the deserts of Texas and northern Mexico (see the excellent map of its known habitat from the Thelocactus site), so it’s in no danger of disappearing… either from habitat or from admiring eyes of home growers.

Thelocactus bicolor is widespread in Northern Mexico shown on this beautiful map at http://www.thelocactus.cactus-mall.com/Thelocactus_Site.html