Lepraria caesioalba (de Lesd.) J.R. Laundon var. caesioalba
Nomenclatural data
Lichenologist 24: 324 (1992)
Crocynia caesioalba de Lesd., Bull. Soc. Bot. France 61: 84 (1914); Leproloma caesioalba (de Lesd.) M. Choisy, Bull. mens. Soc. linn. Lyon II 19: 12 (1950)
Crocynia henrici de Lesd., Bull. Soc. Bot. France 61: 84 (1914)
As usual in the Lepraria neglecta group. See detailed description under the morphologically identical L. caesioalba var. groenlandica.
Five chemotypes are recorded in Greenland: (1) with atranorin, fumarprotocetraric and roccellic/angardianic acids (n = 11); (2) with atranorin, the stictic acid complex and roccellic/angardianic acid (n = 17); (3) with atranorin, the stictic acid complex and rangiformic acid (n = 8); (4) with atranorin, the stictic acid complex, roccellic/angardianic and rangiformic acid (n=1); (5) with atranorin and the stictic acid complex only (n = 14).
L. caesioalba comprises several chemotypes, e.g. Leuckert et al. (1995) distinguished three and Tønsberg (2004) five. In this paper, the classification of Leuckert et al. (1995), with additions, is followed, and specimens containing only atranorin and fatty acid(s) are placed in L. borealis as described by Lohtander (1994) and Prigodina-Lukošienë et al. (2003). The presence of atranorin and fumarprotocetraric acid or stictic acid complex is considered diagnostic.
Ecology and distribution

On soil and bryophytes, sometimes overgrowing other lichens, rarely on rocks.
L. caesioalba var. caesioalba is reported here as new to Greenland. It is widely distributed both in the Low and High Arctic (with more localities in the Low Arctic) but absent from the north coast.
Saag, L., Hansen, E. S., Saag, A. & Randlane, T. 2007.