Leprocaulon subalbicans (I.M. Lamb) I.M. Lamb & A. Ward
Nomenclatural data
J. Hattori Bot. Lab. 38: 534 (1974)
Stereocaulon subalbicans I.M. Lamb, in Imshaug, The Bryologist 60: 220 (1957)
Morphology
White to pale grey, usually with blue („cold“) tinge; minutely fruticose, at least in some places, but granules often confluent and pseudopodetia sometimes almost indistinguishable; whole thallus usually only a few mm tall including pseudopodetia; often forming a thick crust on substrate, reminding thalli of the Lepraria neglecta group except for the presence of small phyllocladia and the diameter of granules; central axis in the pseudopodetia not differentiated; phyllocladial granules coarse, hard, 150–300 µm in diam. For a detailed description see Lamb & Ward (1974).
Chemistry
Lamb & Ward (1974) distinguished 4 chemical strains with additional deficient sub-types („phases“) in L. subalbicans: (I) with atranorin, psoromic, conpsoromic and divaricatic acids plus one unknown substance; (II) with atranorin, protocetraric acid, unidentified fatty acids and two unknown substances; (III) with atranorin, thamnolic acid and unidentified fatty acids; (IV) with atranorin, squamatic and baeomycesic acids and unidentified fatty acids. In the present study, four chemotypes were found: (1) with squamatic, baeomycesic and roccellic/angardianic acids (n = 118); (2) with squamatic and baeomycesic acids only (n = 3); (3) with atranorin, thamnolic and roccellic/angardianic acids (n = 2); (4) with thamnolic and roccellic/angardianic acids (n = 11). The chemotypes (1) and (2) belong to the strain IV and the chemotypes (3) and (4) to the strain III sensu Lamb & Ward (1974). Atranorin which is a constant component of full chemical spectra of all strains according to Lamb & Ward (1974), is reported missing in some deficient phases by these authors, for instance strain III, deficient phases I and II and strain IV, deficient phase II. Atranorin is usually lacking in the Greenland material.
Remarks
See discussion under L. albicans.
Ecology and distribution

Greenland
On soil and bryophytes, sometimes overgrowing other lichens, rarely on rocks.
Thamnolic acid chemotypes are known to be common in USA and Canada, whereas chemotypes with squamatic and baeomycesic acids are relatively rare on the world scale (Lamb & Ward 1974, Brodo et al. 2001, McCune 2004). The different chemotypes have distinct distribution patterns also in Greenland: thamnolic acid chemotypes are widespread, although scattered, having more localities in High Arctic, while the much more common chemotypes (1) and (2) occur in the south and west, mostly in the Low Arctic.
Species pages available
albicans | gracilescens | subalbicans
Literature
Saag, L., Hansen, E. S., Saag, A. & Randlane, T. 2007.
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