General: Common Name: The Treepelt Lichens. Reflects the strict occurrence over bark and the superficial resemblance to certain pelt lichens (Peltigera). Small stratified foliose lichens, corticate above, noncorticate below, sorediate (in BC), lobes loosely attached, rotund (ours), averaging to 3 mm wide, somewhat thick. Upper surface greyish, bearing minute, appressed woolly hairs. Lower surface whitish, lacking veins, bearing short to rather long rhizines restricted to vicinity of margins or scattered throughout. Medulla white. Photobiont blue-green. Apothecia unknown in B.C. material. Over conifer branches. Notes: Leioderma is primarily a subtropical to temperate genus of the southern hemisphere. It consists of five species, only one of which occurs in North America. For points of distinction with similar genera, see the descriptions under Pannaria and Peltigera.
Comments: This essentially South Pacific lichen is known in only two localities in North America — Vancouver Island and coastal Oregon.
