views updated

Caloplaca (order Teloschistales) A genus of lichens in which the thallus is crustose, sometimes with radiating lobes, and is frequently bright yellow or orange. The apothecia are typically yellow, orange, or rust-coloured. Spores are colourless, and generally have a thick wall across the middle which is perforated by a narrow canal. There are many species, found on a range of substrates, including rocks, bark, etc.