Columnea fimbricalyx

Photo by Christian Feuillet
Courtesy of the Smithsonian Institution

Also known as Trichantha fimbricalyx.  Another species with a fimbriate calyx is C. minor.  While the complete function of these elaborate calyx structures is unclear, they may serve as an aide in pollination -- the increased presence of a brightly colored "target" may help hummingbirds find the flowers.