Nephromopsis leucostigma (Lév.) A. Thell & Randlane
Nomenclatural data
Mycol. Progress 4(4): 311, 2005. – Cetraria leucostigma Lév., in Jacquemont, Voyage dans l’Inde Bot.: 180, 1841–1844.­– Type: India orientalis, dédit J. H. Léveillé (H-NYL 36 083! – neotype, proposed by Awasthi 1983). – Platysma leucostigmeum (Lév.) Nyl., Mém. Soc. Sci. Nat. Cherbourg 5: 100. 1858. – Cetraria sikkimensis Räsänen, Arch. Soc. Zool. Bot. Fenn. Vanamo 5: 25, 1950. – Type: [India] Sikkim, Chhangu, alt. ca. 3900 m, on branches of Rhododendron shrub, 05.1947, D. D. Awasthi 355 (H – holotype, Herb. Awasthi – isotype)
Thallus dorsiventral, suberect to erect, 3–5(8) cm high, irregularly branched; lobes plane or involute, of medium size, 5–7(10) mm broad, with undulate margins; upper surface yellow to pale brown, lower surface shiny, brown with occasional yellowish patches. Pseudocyphellae laminal, round or oval, ca. 0.3 mm in diameter, white, plain or concave, present on the lower surface only; rhizines, isidia and soredia absent. Medulla white. Apothecia rare, marginal, round to oblong, 16 x 6 mm; ascospores ellipsoid, 8–9 x 6 µm (according to Awasthi 1983; ascomata not seen in present work). Pycnidia black, on emergent marginal projections; pycnoconidia not seen.
Typical characters. Thallus dorsiventral, yellow on the upper surface and brown on the lower surface. Lobes rather wide (up to 7 mm). Pseudocyphellae distinct on the lower side – laminal, round or oval, white.
Contains usnic acid in the cortex; lichesterinic and protolichesterinic acids in the medulla.
For differences from 'C'. melaloma see under that species.
Ecology and distribution
A rare lichen, known only from Bhutan, India and Nepal (Awasthi 1983, 1988). Not recorded from Tibet but most probably occurs there. Grows on soil or on twigs of shrubs (Rhododendron) in alpine areas at altitudes of 3500–4500 m.
Randlane, T. & Saag, A. 1992. | Randlane, T. & Saag, A. 1998. |Randlane, T. & Saag, A. 2004. | Randlane, T., Saag, A. & Obermayer, W. 2001. | Randlane, T., Saag, A., Thell, A. & Kärnefelt, I. 1994. | Randlane, T., Thell, A., & Saag, A. 1995. | Thell, A., Randlane, T., Saag, A. & Kärnefelt, I. 2005.