Coenogonium is a genus of filamentous lichens in the monotypic family Coenogoniaceae. It has about 90 species. Most species are leaf-dwelling or grow on bark, although a few are known to grow on rocks under certain conditions, and some are restricted to growth on termite nests. The genus was circumscribed in 1820 by German naturalist Christian Gottfried Ehrenberg.

Coenogonium has a worldwide distribution, with most species known from tropical areas. Most species grow in tropical rainforests in the shaded understorey. They typically grow on tree trunks, branches, lianas, and leaves.

...