Turbinicarpus

Turbinicarpus
Turbinicarpus knuthianus
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Caryophyllales
Family:	Cactaceae
Subfamily:	Cactoideae
Tribe:	Cacteae
Genus:	Turbinicarpus (Backeb.) Buxb. & Backeb.
Species
See text.

Turbinicarpus is a genus of very small to medium-sized cacti, which inhabit the north-eastern regions of Mexico, in particular the states of San Luis Potosí, Guanajuato, Nuevo León, Querétaro, Hidalgo, Coahuila, Tamaulipas and Zacatecas.

Ecology

These succulent plants grow mostly on limestone soil (never on volcanic soil), at altitudes between 300 and 3300 meters above sea level. Turbinicarpus are usually confined to specific habitats, generally hostile for the majority of plants, mostly in very drained rocky areas, composed of limestone, sandstone, schist (neutral or alkaline), or in very acidic and humiferous underwood, or in gypsum veins, sometimes so pure that is almost white. In particular, Turbinicarpus strictu sensu are adapted to extreme niches: more than 80% of the species grow in rock cracks or among the pebbles beneath them, where enough dust accumulated to enable root development. It would seem almost impossible that plants so small could survive in such an environment, however in those species that inhabit dry and exposed areas, the root is very thick, becoming a taproot and acting like an anchor on the slopes but, more important, as a water storage for the dry periods, capable of significantly retracting into the ground so that the stem is less exposed to the sun; the spines are often changed to adopt a very papery structure, capable of absorbing good quantities of water. Furthermore, the general look is extremely mimetic, thanks to the epidermis colour and the interlacing spines, guaranteeing a certain protection from eventual herbivores.

Taxonomy

The taxonomic history of the genus Turbinicarpus is rather complex and often mixed with that of other genera like Echinocactus, Echinomastus, Gymnocactus, Mammillaria, Neolloydia, Normanbokea, Pediocactus, Pelecyphora, Strombocactus, Thelocactus and Toumeya, as the results of almost two centuries of constant evolution in the understanding of the affinities and relationship inside the Cactaceae family. Many points of view about the classification of Turbinicarpus are available currently, but the most convincing appear the genus revision by Davide Donati (2003, and 2004 with Carlo Zanovello), thanks to its thoroughness. This work is based on:

• carpology
• chorology
• DNA analysis
• ecology
• flower characters
• intercrossing test, to test the concept of biological species
• morphology
• ontogeny of the entire body and above all of the spination
• seed characters

At the end of that study, Rapicactus is considererd as a distinct genus from Turbinicarpus. The genus Turbinicarpus is subdivided in 2 subgenera at the light of the results of the DNA analysis, and in many series because of the ontogeny of the spination.

Species list

Genus Turbinicarpus

Subgenus Turbinicarpus

Serie Gracilis

• Turbinicarpus dickisoniae
• Turbinicarpus gracilis
• Turbinicarpus hoferi
• Turbinicarpus swobodae

Serie Lophophoroides

• Turbinicarpus alonsoi
• Turbinicarpus bonatzii
• Turbinicarpus flaviflorus
• Turbinicarpus knuthianus
• Turbinicarpus jauernigii
• Turbinicarpus laui
• Turbinicarpus lophophoroides
• Turbinicarpus rioverdensis

Serie Macrochele

• Turbinicarpus macrochele
• Turbinicarpus macrochele subsp. frailensis
• Turbinicarpus macrochele subsp. polaskii
• Turbinicarpus macrochele subsp. valteri

Serie Turbinicarpus

• Turbinicarpus klinkerianus
• Turbinicarpus klinkerianus subsp. schwartzii
• Turbinicarpus klinkerianus subsp. hiemalis
• Turbinicarpus klinkerianus subsp. planiziei
• Turbinicarpus schmiedickeanus
• Turbinicarpus schmiedickeanus subsp. rubriflorus
• Turbinicarpus schmiedickeanus subsp. andersonii

Serie Valdeziani

• Turbinicarpus pseudopectinatus
• Turbinicarpus valdezianus

Serie Gymnocactus

• Turbinicarpus nieblae
• Turbinicarpus saueri subsp. saueri
• Turbinicarpus saueri subsp. nelissae
• Turbinicarpus ysabelae

Serie Viereckii

• Turbinicarpus gielsdorfianus
• Turbinicarpus major
• Turbinicarpus viereckii subsp. viereckii
• Turbinicarpus viereckii subsp. neglectus

natural hybrids

• Turbinicarpus × mombergeri (pseudopectinatus × laui)

Subgenus Kadenicarpus

Section Bravocactus

• Turbinicarpus horripilus

Section Kadenicarpus

• Turbinicarpus krainzianus
• Turbinicarpus krainzianus subsp. minimus
• Turbinicarpus pseudomacrochele

Genus Rapicactus

Subgenus Rapicactus

• Rapicactus beguinii
• Rapicactus beguinii subsp. hintoniorum
• Rapicactus booleanus
• Rapicactus canescens
• Rapicactus donatii
• Rapicactus subterraneus
• Rapicactus zaragosae

Subgenus Lodia

• Rapicactus mandragora
• Rapicactus pailanus

Synonymy

The following genera haven been brought into synonymy with Turbinicarpus:

• Gymnocactus Backeb.
• Normanbokea Kladiwa & Buxb.

References

• D. Donati & C. Zanovello, Knowing, understanding, growing Turbinicarpus-Rapicactus (Ed. Cactus Trentino SudTirol, 2005) pp. 254
• Edward F. Anderson, The Cactus Family (Timber Press, 2001), pp. 665-673
• Grupo San Luis, The Genus Turbinicarpus in San Luis Potosì (Ed. Cactus&Co, 2004)

External links

• "Alkaloids and why Turbinicarpus sp. contain them" (Turbinicarpus Information Exchange)
• ("Lost Peyotls")