Systematics of Glossoloma (Gesneriaceae)

The genus Glossoloma (Gesneriaceae; subfamily Gesnerioideae; tribe Episcieae) comprises 27 species and occurs from southern Mexico to Panama, northwestern South America, and south to Bolivia. It ranges in elevation from sea level in the Chocó forests of northwestern South America to 3500 meters in the Andean cloud forests of Colombia and Ecuador. The center of diversity of Glossoloma is found in the western lowland forests in Ecuador and Colombia, where 15 species occur. The habit ranges from unbranched terrestrial subshrubs and herbs to occasionally facultative epiphytes; two species are obligate epiphytes. Nearly all species of Glossoloma have resupinate flowers with laterally compressed tubular corollas that are apically pouched. The generic circumscription of Glossoloma is based on phylogenetic analyses of morphological and molecular data from the ribosomal (nrDNA) internal transcribed spacer region (ITS) and the intergenic (trnH-psbA) chloroplast spacer region (details of the analyses are published separately). Glossoloma includes the majority of species that had been traditionally recognized as Alloplectus, a poorly defined genus with discordant elements currently nesting in Columnea, Nematanthus, Drymonia, and the resurrected genus Crantzia. Replacing the traditional polyphyletic concept of Alloplectus with a monophyletic Glossoloma resulted in 21 new combinations, which were published previously. Five new species are proposed: Glossoloma anomalum, G. harlequinoides, G. pedunculatum, G. scandens, and G. subglabrum. A lectotype is designated for Alloplectus penduliflorus (=Glossoloma penduliflorum). Full synonymies and descriptions, and a key are provided; all species are mapped, and most are illustrated.