Bottlebrush Frost Lichen

Physconia detersa is a foliose lichen in the Physciaceae. Thallus pale gray-brown to dark red-brown, uniform and often shiny except for the white pruina on the lobes (sometimes confined to the tips); lobes flat to slightly up-turned and partly overlapping, (0.6-)1-2(-3) mm broad, bordered with marginal soralia containing brown to gray-green soredia (except for the growing tips); medulla white; lower surface black producing a thick mat of black, densely branched (like a bottle-brush) rhizines. Apothecia rare.