Turbinicarpus valdezianus is one of the smallest and slowest-growing cactus—small even within genus Turbinicarpus, not known for their tremendous size. The diminutive body is the size and shape of a thimble. The spines are minute, almost microscopic, and flattened against the body in harmless tight formation—more like scales than armament. Flowers are pink, often striped; occasionally white.

Turbinicarpus valdezianus is found in Coahuila, San Luis Potosí, Nuevo León, and Zacatecas.

Turbinicarpus valdezianus showing more of body

Correction: The plant was originally identified as Turbinicarpus valdezianus. A fallen label was discovered, and this plant is the related Turbinicarpus pseudopectinatus.

Even if you limit yourself to the most seductive cacti from genus Mammillaria, you still have dozens of strange and wonderful plants to choose from. Mammillaria pectinifera (Latin for “comb-bearing”) has such minute, harmless spines that they appear like legs on tiny bugs—reminiscent of the spines on Mammillaria hernandezii (profiled previously). The spine beds are elongated vertically, like so many miniature millipedes marching in tight formation.

Surprisingly, Mammillaria pectinifera is most closely related to M. carmenae (which looks completely different; also profiled on Sentient Meat), M. glassii, M. picta, M. plumosa, and M. prolifera. Together these species plants form a clade, a group of types likely descending from a common ancestor. They differ markedly from each other in size, spines, and other features.

Mammillaria pectinifera, endangered miniature cactus native to Puebla, Oaxaca. Plant grown and photographed by Mr Sentient Meat

My plant is just over an inch in diameter. This is its first bloom under my care. The flowers are an elegant pale pink. Overall the plant is neat and understated in appearance.

Mammillaria pectinifera, same plant viewed close up, plant grown and photographed by Mr Sentient Meat

Mammillaria pectinifera‘s appeal may be its downfall. It has reportedly been collected nearly to extinction within its native Puebla, Oaxaca, Mexico. Consequently, it’s protected under CITES I, the most stringent protocol of international protection.

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.

Ariocarpus scaphirostris, extremely rare, occurring only on the Valley of Rayones, Nuevo Leon, Mexico. It is endangered by unscrupulous collectors… and reportedly by goats, which damage their habitat. This 2-inch plant is probably at least 8 years old — minimum flowering age.

I was in the full throes of enthusiasm when I obtained this rather costly little plant. By enthusiasm I mean the old sense of  divine inspiration or frenzy. This frenzy — probably a dopamine buzz — always grips me in the sales area at cactus and succulent plant shows. To my friends, I apologize if I seem dizzy or distracted. It’s because my mind is bathed in an unseen, golden haze.

It’s both embarrassing and enthralling to be an enthusiast — almost any kind of enthusiast, but particularly a plant enthusiast. Embarrassing because it’s so personal, so particular, so quaint, so… geeky. Enthralling because the object of our enthusiasm brings such immediate fascination, such transfixing attention, such passion.

As soon as you reveal a passion, you make yourself vulnerable — this is true with any declaration of love. How much moreso with plants? For one thing, the love is always unrequited. And it’s such an obscure, unusual love. It’s a little like loving, say, mathematics. (Guilty!) And yet it’s much more humble, more homely, almost banal… literally down in the dirt. Face it, you are out on a limb — a plant limb — and it feels awkward.

Same plant in full bloom 3 days later. In habitat, only the tips of the leaves (and flower) would be visible above the gypsum shale scree. (And yes, I just enjoy writing gypsum shale scree.)

Like most passions in life, if you have to explain it, no words will suffice; yet to another enthusiast, no words are necessary. The beauty of the forms, the plants’ names and stories, the technical details of habitat and how to care for the plants — these crossbeams interlock to build first a frame and then a fully furnished room in the house of one’s life (or at least to take over the backyard… sorry honey!).

Today’s plant, Ariocarpus scaphirostris (also spelled scapharostrus for historical reasons) is an obscure beauty — literally obscure. In nature it spends its entire life hidden underground with only the tips of its tubercles exposed (those thick protuberances). And even its tubercles when dusty blend perfectly into the landscape, looking exactly like the shards of gypsum shale which litter its habitat.

This complete camouflage is demonstrated almost miraculously in — of all things — a YouTube video.

Ariocarpus scaphirostris is also obscure because it lives in such a limited area, only Valle de Rayones, Nuevo Leon, Mexico. This rare plant is endangered by collectors and, it turns out, by goats which range the slopes where it lives and damage the landscape. Luckily more and more folks in Mexico (and internationally) are coming to recognize the irreplaceable resource of Nuevo Leon‘s native plant life, including this almost invisible geophyte (plant living mostly underground).

Ariocarpus scaphirostris is vulnerable, but its outlook is improving modestly as passionate individuals raise its conservation profile in Mexico and the rest of the world. This plant is small, it’s slow, it’s difficult, and it’s hard to come by. Most of the year it looks like twisted green rocks. But I think it’s beautiful, and this was its first flower under my care.
–
Ariocarpus scaphirostris at CactusArt.biz
Ariocarpus scaphirostris at CactiGuide.com
Ariocarpus scaphirostris at Living Rocks of Mexico