Neomartensia (Spermacoceae, Rubiaceae) género nuevo de México

摘要

The new genus is based on Declieuxia galeottii M. Martens described in 1844. Its taxonomic position has been doubtful up to now. Kirkbride excluded it from Declieuxia (1976) and it was transferred into four different genera (Manettia in 1927, Hedyotis in 1989, Bouvardia in 2008, and Mexotis in 2009). The new genus is related to Bouvardia subgen. Bouvardiastrum (Schltdl.) Blackwell - belonging to Spermacoceae instead of Hedyotideae - with oblate loculicidal capsule and subcircular to ellipsoid compressed seeds with narrow wing, but differs in having small white flowers with funnel-form corollas, corolla tube mostly naked at the base inside (hairy in B. albiflora) and with long haired villous throat and corolla lobes inside. The description of Bouvardia macdougallii Lorence (1994) and the discovery of further three species (Borhidi et al. 2008) with the same character combination of the floral features convinced the authors of this paper to separate this five membered species group at generic level, dedicating it to the honour of M. Martens, the author of the first described species of the new genus.