A new plant genus and species from south-eastern Spain: Castrila latens (Rubieae, Rubiaceae)

Abstract

A new genus and species, Castrila latens, native to the south-eastern Iberian Peninsula, is described here for the first time and compared with its closest relatives. The plant is characterized by being annual, glabrous, having reduplicate leaves in whorls of (5)6–7, inflorescences capitate and involucrate, corolla shortly hypocrateriform and white, with yellowish doliiform tube, stamens included, and ovary and mericarps densely papillose. An endemic plant, it grows on the calcareous mountains of the Sierra Seca, Sierra de Castril, and Sierra de la Cabrilla, between 1800 and 2100 m of elevation, in the Granada and Jaén provinces (eastern Andalusia, Spain). For this genus and species, a description, an illustration, a distribution map, the chromosome number, the assessment of the conservation status, an estimate of the breeding system, and the situation in the Rubieae phylogenetic tree are provided.