Abstract

ARROYO-COSULTCHI, Gabriel; TERRAZAS, Teresa; ARIAS, Salvador  and  LOPEZ-MATA, Lauro. Delimitation of Neobuxbaumia mezcalaensis and N. multiareolata (Cactaceae) based on multivariate analyses. Bol. Soc. Bot. Méx [online]. 2010, n.86, pp.53-64. ISSN 0366-2128.

Neobuxbaumia multiareolata and N. mezcalaensis are taxa poorly defined, despite the second species was described originally as a variety of first. Although several classification proposals indicate that they represent different species, in the most recent cacti classification, both are considered a single species. The working hypothesis is that there are morphological characters that allow to separating N. mezcalaensis and N. multiareolata. Multivariate analyses were performed, with a total of 15 populations, to test if a boundary between N. mezcalaensis and N. multiareolata exists, and to compare the morphological characters with those of N. squamulosa and N. polylopha. The results allowed recognizing that intermediate phenotypes do not exist and that individuals of each analyzed populations were classified in their respective species. The areole size and form, central spine length and distribution pattern of the radial spines, plus four characters mentioned previously by other authors, allowed to differentiate N. mezcalaensis from N. multiareolata. Based on these evidences we propose that they represent independent species.

Keywords : Canonical discriminant analysis; columnar cacti; morphometrics; radial spines.

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