Authors: Kvist, Lars Peter; Skog, Laurence E.
Publication: Smithsonian Contributions to Botany
Year: 1992
Genera: Kohleria

The genus Kohleria (Gesneriaceae: Gloxinieae) ranges from Mexico to Peru and east to Surinam, and from sea level to about 2500 meters altitude, but most commonly grows between 800 and 2000 meters. About 100 species have been described in Kohleria, but in the present work only 17 are recognized. Fourteen species occur in Colombia, with 9, including four newly described species, K. diastemoides, K. grandiflora, K. longicalyx, and K. neglecta, being endemic to this country.

Eleven Kohleria species occur in exposed, disturbed habitats along rivers, roads, etc. These species have capsular fruits that split apically into two valves and have wind-dispersed seeds. In contrast, the remaining species are found in shaded, humid forest understory, and have capsules that split by a slit from the apex to the base to expose a sticky mass of seeds that apparently are animal-dispersed. These latter species also usually lack the scaly rhizomes that enable exposed-habitat species to survive dry spells.

Some Kohleria species are stable in most features even over wide distribution ranges, e.g., K. spicata and K. tubifora. In contrast, a few species are surprisingly variable. To circumscribe this variation the following varieties are recognized: K. amubilis var. bogotensis, K. hirsuta var. longipes, K. villosa var. anisophylla, K. inaequalis var. ocellata, and var. lindenii (none of these are new taxa). Kohleria hirsuta and K. trianae hybridize in the Central Colombian Cordillera. In the Eastern Colombian Cordillera, var. longipes of K. hirsuta may be a formerly well-separated semi-species that has hybridized extensively with the typical variety. The most variable species K. inaequalis apparently is a complex of three extensively hybridizing semi-species, and pure breeding populations still are found in the periphery of its range. Generally, the main mode of speciation of Kohleria appears to be the geographical isolation of peripheral populations, while hybridization breaks down species limits rather than creating new ones.