Identification of a new genus within the subtribe Gloxiniinae (Gesneriaceae).

Abstract

Morphological and molecular analyses within the subtribe Gloxiniinae have led to the discovery of several previously undescribed genera. One of these genera comes from studies of the species Diastema vexans H.E. Moore, which has been identified from central to south Colombia. The nomenclatural history of the species has been very confused due to multiple species being designated under the same name. Morphological studies of the species and other closely related plants to confirm the species identification has provided evidence of a differing evolutionary lineage leading to the group. These studies have also revealed three new species that are distributed from Colombia southward through Peru. These taxa are identified by a suite of characters including axillary inflorescences, orbicular calyx base, and cup-shaped fruits. The traits are not seen among the other species of Diastema and this grouping represents a new genus in the tribe. Recent molecular studies have provided support to show that the flower shape and color of Diastema vexans and congeners is due to convergence through pollinator selection. Ongoing molecular and morphological research will be used to confirm the placement of the new genus Regeliantha within the subtribe Gloxiniinae.