Turbinicarpus

Genus scope and historical names

Plants of the World Online accepts 14 species of Turbinicarpus and three additional named hybrids. The genus occurs naturally in Mexico. The accepted species are T. alonsoi, T. boedekerianus, T. gielsdorfianus, T. graminispinus, T. hoferi, T. laui, T. lophophoroides, T. nikolae, T. pseudopectinatus, T. saueri, T. schmiedickeanus, T. swobodae, T. valdezianus and T. viereckii. The list reflects the database checked on 10 October 2026. [2-WWW]

In older accounts, Turbinicarpus also included present-day Rapicactus and Kadenicarpus. Examples are Rapicactus subterraneus (formerly Turbinicarpus subterraneus) and Kadenicarpus pseudomacrochele (formerly T. pseudomacrochele). The 2019 analysis combined plastid DNA data with morphological and anatomical features, recognising three separate evolutionary lineages. This separation also organises study results published under older names. [Vázquez-Sánchez et al. 2019] [2-WWW]

The names Gymnocactus and Normanbokea appear in the classification history of species remaining in Turbinicarpus today. Boundaries of these former groups were based in part on spine delicacy and seed structure. A small spherical stem and areoles at tubercle tips occur in several Cacteae lineages, so similarity in these features requires comparison with organ structure and molecular results. [Vázquez-Sánchez et al. 2019] [2-WWW]

Tubercles, spines, flowers and seeds

Stems are small, usually spherical, flattened or shortly cylindrical. Their surface consists of distinct tubercles, with an areole at each tip. Spines differ in width, stiffness and microstructure. In T. valdezianus, their epidermal cells form long projections giving a feathery appearance. In part of the T. schmiedickeanus complex, thin-walled tissues dominate, and spines take on a papery or corky texture. [Vázquez-Sánchez et al. 2019] [Mosco 2009]

Flowers have a short tube and develop on the stem. The perianth may be white or pink in the historically described species group. The fruit wall opens through longitudinal slits. Seed-surface microsculpture in Turbinicarpus is striate. This is a feature of the surfaces of individual seed-coat cells viewed at suitable magnification. It differs from the smooth microsculpture of Kadenicarpus and the papillose microsculpture of Rapicactus. A laterally splitting fruit is a feature shared by several genera. [Vázquez-Sánchez et al. 2019, p. 405–406, 409, 412, 416–417]

Water-storing tissues

Beneath the single-layered epidermis lies the hypodermis, one or several cell layers reinforcing the stem surface. In the Turbinicarpus material studied, it contained prismatic crystals. Deeper tissues included photosynthetic parenchyma arranged in a palisade pattern and storage parenchyma. Conduction involved bundles of the main cylinder and smaller bundles passing through the stem cortex. In T. alonsoi and T. lophophoroides, the latter had xylem surrounded by phloem. [De la Rosa-Tilapa et al. 2019, online version, pp. 2–4]

Wood of the species studied in this lineage lacked fibres. Vessels lay among wide-band tracheids, whose walls have broad ring-shaped or spiral thickenings. Non-lignified parenchymatous rays accompanied them. [De la Rosa-Tilapa et al. 2019, wersja online, p. 3–4, 7–9]

Habitats and ecological differences

The diversity centre of the former turbinicarpi lies in the Mexican part of the Chihuahuan Desert and adjacent areas. The 2019 publication discusses the association of many populations with limestone, gypsum or saline substrates. A mosaic of rocks and isolated sites favours local taxa. Individual species occupy different microhabitats. [Vázquez-Sánchez et al. 2019, p. 415]

Donati and colleagues' biogeographical analysis compared herbarium and locality-database information with climate, substrate and morphology. The abstract indicated higher sites for Rapicactus than for Turbinicarpus, and the importance of calcium-rich substrates. Distribution of recorded taxa was also associated with field-sampling intensity. The species-richness map therefore needs to be read alongside information on observation distribution. [Donati et al. 2017, abstract]

Propagation and retaining material

Laboratory studies demonstrated propagation of several species by stimulating areoles in seedling fragments. Dávila-Figueroa and colleagues compared eight taxa, including present-day Rapicactus subterraneus (described as Turbinicarpus subterraneus). Multiplication, rooting and acclimatisation were separate stages. The available abstract describes differences in responses to culture medium among the taxa studied. [Dávila-Figueroa et al. 2005, abstract]

For a collection raised from seed, retaining the name, field number and batch origin matters. In the 2019 analysis, the T. schmiedickeanus, T. saueri and T. viereckii complexes did not form groups matching all subspecies boundaries recognised at that time. Weak resolution of some branches and incomplete population sampling limited the possibility of a final revision. Current names allow a taxon to be found, while provenance data retain the biological context of its material. [Vázquez-Sánchez et al. 2019, pp. 414–415]

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