Psoroma araneosum (C.Bab.) Nyl.
Details
Nomenclature
(C.Bab.) Nyl.
C.Bab.
Nyl.
1859
294
ICN
species
Psoroma araneosum
Classification
Descriptions
Psoroma araneosum (C.Bab.) Nyl.
Thallus large, rosette-forming to spreading, loosely to closely attached, lobate-foliose, free at margins, without a prothallus, 5-12(-20) cm diam. Lobes broad, 5-20 mm wide, coriaceous, margins rounded, sinuous often crisped, ascending, overlapping, conspicuously thickened. Upper surface uneven, matt centrally, coarsely scabrid near margins and regularly marginally tomentose, tomentum white, arachnoid, pubescent, plant bright green when wet, pale greenish-grey or pale greenish-fawn when dry. Medulla white. Lower surface whitish, naked or very finely tomentose, striate, with occasional tufts of pale buff, squarrose rhizines centrally. Cephalodia frequent to moderate, small, globose, ± granular to subplacodioid, 1.3 mm diam., pale whitish-grey, laminal, densely wrinkled-plicate. Apothecia sessile, laminal, often crowded centrally 1-5 mm diam., margins concolorous with thallus, thick, crenulate-striate, disc plane or subconcave, chestnut-brown to dark red-brown, smooth, matt, epruinose, not gyrose-contorted, without fissures or thalline lobules, thalline exciple wrinkled-verrucose. Ascospores ellipsoid, 12-16 × 8-9 µm.
Taxonomic concepts
Psoroma araneosum (C.Bab.) Nyl.
Psoroma araneosum (C.Bab.) Nyl.
Collections
Metadata
7d283265-6b56-4acf-a117-8c43523cc120
scientific name
Names_Plants
1 January 2000
9 March 2010