Status and scope
Astrophytum myriostigma subsp. myriostigma is the nominate subspecies, including the element associated with the species name's type. POWO includes columnare, nudum, potosinum, strongylogonum and tulense in their respective historical combinations among its synonyms. Assigning a particular plant to a subspecies should account for provenance and the adopted taxonomic treatment. [2-WWW]
Morphology and environment
Plants vary in slenderness, hair density and rib number. In the narrower treatment used in the 2021 study, the nominate subspecies was compared with the separately recognised tulense group. Broader stems, larger seeds and flowers with more tepal rows were described on average. The current POWO treatment encompasses broader variation than this comparative group. [Montanucci and Kleszewski 2021] [2-WWW]
Populations were studied at various sites in San Luis Potosí, Nuevo León and Tamaulipas. Hair features range from dense cover to an almost bare surface. The nudum paper did not confirm a feature set supporting treatment of all bare plants as a separate geographical subspecies. [Montanucci and Kleszewski 2020] [Montanucci and Kleszewski 2021]
Cultivation and identification
The principles in the A. myriostigma profile apply. Bare forms require careful light acclimation, and older columnar plants a stable pot. Sowing a batch from a documented site allows observation of actual population variation. Keep label names, such as tulense or columnare, as historical or provenance information alongside the current assignment. [Szychowski b.d.c] [Montanucci and Kleszewski 2020] [Montanucci and Kleszewski 2021] [2-WWW]