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| Mammillaria morentiniana Gonz.-Zam., D. Aquino, J. Mohl & Dan. Sánchez, in González-Zamora, Aquino, Mohl & Sánchez, 2022. |
Abstract
We describe a new endemic densely spined Mammillaria from San Luis Potosí, Mexico. The new species, named M. morentiniana, is distinctive by the presence of a globose to shortly cylindric stem with several glabrous, reddish central spines, radial spines that protrude from the plant like white needle-bristles, and small flowers with pale yellow, lanceolate tepals. We compare it with similar and sympatric species of M. ser. Stylothelae. We include data about habitat and the preliminary status of conservation of the new taxon.
KEYWORDS: Cactaceae, Cacteae, Mammillaria, Mammillaria ser. Stylothelae, Mexico, morphology, multivariate statistics, new species, species delimitation
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| Morphology of Mammillaria morentiniana during dry and rainy seasons. – A: plant flowering in habitat; B: stem and roots; C: stems during dry season covered by radial spines resembling white needle-bristles; D: stems during rainy season showing hydrated and expanded tubercles; E: close-up of tubercle and areole bearing six central spines; F: plant bearing red and claviform fruits; G: flower in longitudinal section, outside and inside views; H: seeds. – Scale bars: A = primary graduations of 1 cm, secondary graduations of 1 mm; B = 10 mm; E = graduations of 0.5 mm; G = 10 mm; H = 1 mm. |
Mammillaria morentiniana Gonz.-Zam., D. Aquino, J. Mohl & Dan. Sánchez, sp. nov.
Holotype: Mexico, San Luis Potosí, Santa María del Río, 2056 m, 28 Aug 2019, P. González-Zamora 11 (IBUG 215375; isotype: SLPM).
Diagnosis — Mammillaria morentiniana is distinguishable from M. bocasana, M. crinita and M. nana by the presence of more than 4 central spines (mean = 5), and differs from M. schwarzii, which presents, on average, 7 thinner central spines (Supplemental content online; Fig. 2). Mammillaria morentiniana bears fewer than 32 straight radial spines (mean = 24.49), whereas M. schwarzii bears more than 32 straight radial spines (mean = 38.98). Mammillaria morentiniana has completely red central spines and black, non-arillate seeds, whereas M. bocasana has red central spines with a yellow base and reddish brown, arillate seeds. Mammillaria morentiniana has glabrous spines and straight radial spines, whereas M. crinita has pubescent spines and tortuous or straight radial spines. Mammillaria morentiniana differs from the sympatric M. nana because the latter has tuberous roots and 0 or 1 pubescent central spines.
Etymology — The specific epithet is dedicated to the Morentín family from Colima, Mexico. Don Marco and Doña Laura spent their lives preserving the flora in W Mexico. They inspired the first author to observe and admire the local and xerophytic flora.
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| Comparison of the stem (left), areole, central and radial spines (right) in the populations of Mammillaria ser. Stylothelae included in the analysis. – A: Mammillaria sp.; B: M. bocasana (bocasana_SLP); C: M. bocasana (bocasana_SLP2); D: M. crinita (c_crinita_QRO); E: M. crinita (c_crinita_QRO2); F: M. crinita (c_crinita_GTO); G: M. crinita subsp. leucantha (c_leucantha); H: M. crinita subsp. wildii (c_wildii); I: M. nana (nana); J: M. schwarzii (schwarzii). – Scale bars: A–E, G, I, J = graduations of 1 mm; F, H = 10 mm. |
Pedro González-Zamora, David Aquino, Jonathan Mohl and Daniel Sánchez. 2022. A New Endemic Species of Mammillaria (Cactaceae) from San Luis Potosí, Mexico. Willdenowia. 52 (3); 359-372. DOI: 10.3372/wi.52.52305
