Oehmea tonalensis

Historia nazwy

The name accepted by POWO is Oehmea tonalensis (D.R.Hunt) Guiggi. David R. Hunt described the taxon as Mammillaria tonalensis. Its classification history also includes the name Escobariopsis tonalensis. Guiggi published the combination in Oehmea in 2022. The former names lead to the same species in the atlas. [2-WWW] [Guiggi 2022, POWO, as of 11 October 2026. Guiggi, p. 3]

Stem, spines and flowers

Hunt's description presents branched, erect or decumbent stems 2–2.5 cm in diameter, exceptionally 3.5 cm, and fibrous roots. The tubercles are light green, and the axils glabrous or sparsely woolly. One hooked central spine reaches up to 18 mm, while nine to twelve straight radial spines reach up to 1 cm. [Hunt et al. 2006, p. 177; Mammillaria tonalensis]

The flowers are about 15 mm long and 10–12 mm in diameter. The inner tepals are carmine with whitish margins, and the outer tepals brownish-pink. The fruits are bright red and the seeds black. [Hunt et al. 2006, pp. 177–178]

Material from Oaxaca

POWO gives a native range restricted to the Mexican state of Oaxaca. The plant is a succulent subshrub assigned to desert or dry scrub environments. Guiggi's nomenclatural documentation refers to Alfred B. Lau's material from near Puente Tonalá in Oaxaca, bearing the number 1114. This collection number helps connect older descriptions with herbarium documentation. [2-WWW] [Guiggi 2022, Guiggi, p. 3]

Hunt's documentation identifies steep limestone rocks with sparse shrub cover near Puente de Tonalá. [Hunt et al. 2006, p. 177, site of the type material]

Taxonomic comparison

In the 2022 note, Guiggi points to morphological similarity with Oehmea sphacelata, referring to Hunt's earlier account. This cited relationship forms part of the justification for assigning it to the genus. The accepted POWO treatment retains O. tonalensis and O. sphacelata as separate species. [Guiggi 2022, Guiggi, p. 3] [2-WWW] [2-WWW]

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