Lepraria vouauxii (Hue) R.C. Harris
Nomenclatural data
Harris, in Egan, The Bryologist 90: 163 (1987)
Crocynia vouauxii Hue, Bull. Soc. Bot. France 71: 392 (1924); Leproloma vouauxii (Hue) J.R. Laundon, The Lichenologist 21: 13 (1989)
Crocynia arctica Lynge, Skr. om Svalbard og Ishavet 81: 19 (1940); Lepraria arctica (Lynge) Wetmore, Publs Mich. St. Univ. Mus., biol. ser., 3: 440 (1968)
Leprose, usually cottony, soft, thick; white, cream to greyish cream; thallus margin delimited, sublobed or diffuse; medulla absent to prominent, white, usually present; soredia rather loosely packed, mostly coarse, often with short projecting hyphae.
The diagnostic substance of this species is pannaric acid 6-methylester, often accompanied by a selection of related dibenzofurans and very rarely atranorin (Elix & T√łnsberg 2004). This is also the main pattern in the Greenland chemotypes: (1) with pannaric acid 6-methylester only (n = 44); (2) with pannaric acid 6-methylester and roccellic/angardianic acid (n = 4); (3) with pannaric acid 6-methylester and atranorin (n = 1). Roccellic/angardianic acid as an accessory compound has been reported earlier (Laundon 1989, Leuckert et al. 1995).
L. vouauxii can be quite variable in its thallus characters but is usually recognizable by its consistence and colour in Greenland. The recently described L. gelida (T√łnsberg & Zhurbenko 2006) may resemble this species morphologically and has a similar distribution pattern in Greenland. Still, the pannaric acid 6-methylester content of L. vouauxii makes it distinct from other species.
Ecology and distribution

On soil and bryophytes, sometimes overgrowing other lichens, rarely on rocks.
L. vouauxii is common in Greenland, being distributed discontinuously in the south, northeast and northwest of the island.
Saag, L., Hansen, E. S., Saag, A. & Randlane, T. 2007.