ABSTRACT:

Subsection Rupicola, a new subsection of Anthurium section Calomystrium is proposed, encompassing nine rupicolous species. Descriptions and a key are provided for these species including: A. antrophyoides Killip, from Ecuador and Colombia, A. chocoense Croat and A. antioquiense Engler from Colombia, as well as A. amnicola Dressler, and A. sytsmae Croat from Panama. Five species, A. palacioanum Croat and A. weiffii Croat from Ecuador, and A. chocoense Croat, A. callejasii Croat, and A. vanderknaapii Croat, from Colombia, are described as new. Members of this group were previously thought to belong in section Porphyrochitonium because of their generally lanceolate leaf blades, and stems with short internodes. However, lack of distinct glandular punctations on blade surfaces and the ability to interbreed readily with other members of section Calomystrium indicate that this new group belongs in section Calomystrium, and has evolved without conspicuous posterior lobes typical of section Calomystrium, owing to their rupicolous habitat.