Trapelia

Crustose lichens containing a trebouxioid alga; thallus smooth, cracked, areolate, granular or somewhat lobate; apothecia with a thin but prominent and persistent non-algal rim, sometimes also with a margin of thalline material extending part way up the sides; hymenium colourless or with yellow-brown pigments and sometimes minute crystals dispersed throughout, formed of densely branching and anastomosing paraphyses embedded in gel; hypothecium colourless or yellowish brown; asci narrowly clavate, thin-walled or with a very thin tholus, IKI- or + pale blue; spores 8 per ascus, colourless, simple, elliptical or ovate, often with a single large oil droplet within.

References: Purvis et al. 1992; Lumbsch & Kainz 2004.

Crust of minute goniocysts, dull, deep dark green, lacking soredia; apothecia opaque, monochrome dark red-brown, with a thick rim and a thick and convex disc, not lifting at the margins; spores 9-17 × 6-8  µ; a rare species of inland BC’s rainforests, to be sought in the wettest portions of the study area …[Trapelia interior Björk ined.]