mealy lichen
Leprocaulon albicansDescription 1
Thallus: fruticose, without persistent primary thallus, extensively covering the substrate in a continuous or discontinuous pattern, sometimes low and congested-pulvinate and forming a dense crust-like growth; central axis: well differenttiated, cloudy and opaque, yellowish-gray, composed of longitudinally parallel hyphae 2.5-3.0 micrometer diam. with outer wall thinner than lumina; outer mantle 15-25 micrometer thick, of lax hyphae 2.5-3.0 micrometer diam., running chiefly longitudinally, enclosing scattered groups of algae; surface: white, whitish gray, bluish white or cream-colored, without distinct yellowish tinge, chalky, subtly whitish arachnoid-tomentose or partly glabrous, brown or brownish towards base, where often ± dying; pseudopodetia: (2-) 1 (-2.5) cm long, 0.2-0.3 mm thick, crowded-caespitose, erect or interwoven, terete, not dorsiventral; sparingly branched (not dichotomously), not dendroid-plumose; without root-like basal structures; phyllocladial granules: distinctly developed, subglobose, 0.10-0.25 mm diam., chalky-whitish to grayish, dull, subtly powdery but not sorediate, with central mass of algae, without medulla, surrounded by a cloudy and semi-opaque tissue of loosely interwoven and floccose hyphae forming an envelope 12-30 um thick; Spot tests: thallus K- to + faint to distinct yellow, C-, KC-, P+ persistent intense yellow (strains I and III), orange-yellow (strain I) or P+ intense orange-red to scarlet-red (strain II); UV- or (strain III [non-Sonoran]) + blue-white; Secondary metabolites: atranorin (sometimes minor), fatty acids (including rangiformic acid in strains I and II), plus (strain I) psoromic acid chemosyndrome, (strain II) protocetraric acid, or (strain III [non-Sonoran]) squamatic and baeomycesic acids.; Substrate and ecology: on detritus with mosses, or over mosses, on open rock faces or in rock crevices, sometimes on soil among grasses between rocks, in quite exposed situations or in moderately shaded places; World distribution: North America in the west and South America; Sonoran distribution: California, Arizona and Chihuahua, 1800-2250 m (all Strain 1).
Fuentes y créditos
- (c) Lichen Unlimited: Arizona State University, Tempe., algunos derechos reservados (CC BY-NC-SA), http://eol.org/data_objects/10547406
