Callicostella prabaktiana [Tc]

Description

Callicostella prabaktiana is a creeping moss with a wide distribution in the Asian tropics, where it grows on wet rocks and shaded riverbanks, among others. It resembles the species Callicostella papillata very much, however, it can be discerned from the latter by missing papillae (tiny bumps) on the leaf cells as well as a less serrate leaf margin in the tip area. It is often considered a variety of this species, though (C. papillata var. prabaktiana). The creeping, irregularly ramified shoots have a flat leaf pattern and look a bit like those of the Vesicularia species. However, C. prabaktiana can be discerned from the latter e.g. by a thick double midrib reaching almost to the leaf tip, rather roundish, thick-walled leaf cells and its tongue-shaped shortly acute leaf form.