Lobarina Nyl. ex Cromb.
Type : Lichen scrobiculatus Scop. [=Lobarina scrobiculata (Scop.) Nyl. in Cromb.]
Description : Thallus heteromerous, foliose, dorsiventral, lobate, spreading, loosely attached, corticolous, occasionally saxicolous or terricolous. Lobes rounded, overlapping or sometimes broadly laciniate. Upper surface scrobiculate–reticulate but without strongly defined interconnecting ridges, sorediate. Soredia laminal and marginal, in spreading, erose soralia, punctiform on upper surface, ±linear at margins, whitish or greyish, becoming bluish with age, coarse, granular. Medulla white. Photobiont Nostoc. Lower surface white, uneven or ±wrinkled–bullate, not distinctly veined but with naked, whitish scabrid patches scattered among pale- to dark-brown tomentum. Naked parts of lower surface composed of periclinal hyphae; lower cortex plectenchymatous, of round cells with rounded lumina. Tomentum of two kinds: at naked areas of lower surface the surface tomentum is composed of a few chains of rounded cells; elsewhere the tomentum is longer and thicker with tomental cells being cylindrical with rectangular lumina.
Ascomata apothecia, laminal, scattered, sessile, thalline exciple verrucose–areolate. Ascospores colourless, 3-septate, acicular or linear at maturity, 60–65 × 5 μm. Conidiomata pycnidia, similar to those in Lobaria (q.v.).
Chemistry : metadepsides (scrobiculin), stictic acid chemosyndrome and usnic acid – tridepsides absent.
Lobarina was first suggested as a genus name by Nylander (1877) to accommodate Lobaria scrobiculata ["...Stirps Stictae pulmonariae rite distinguenda sit ut genus proprium Lobaria, et tunc Stictina scrobiculata evadit genus Lobarina" (Nylander 1877: 233)], but he failed to provide a description and his name was therefore a nomen nudum. Lobarina was accepted as a subgenus of Lobaria by Vainio (1890: 194), and as a subgenus of Sticta by Jatta (1893: 45). The genus was later validated by Crombie (1894) and is now accepted by Yoshimura (1998a: 90) in his most recent revision of Lobaria. His treatment is followed here. The genus is monospecific, and has a scattered, suboceanic distribution (though often rare and declining) in Great Britain, Scandinavia and Europe, eastern and western North America, East Africa, Japan, Australia and New Zealand (Krog 1968; Yoshimura 1971, 1974; Jordan 1973; Galloway 1985a; Swinscow & Krog 1988; Purvis et al. 1992; Nimis 1993; Santesson 1993; Goward et al. 1994b; Filson 1996; Elix 2001; Coppins 2002b; Nimis & Martellos 2003) where it grows in shaded, humid habitats. It is placed in the family Lobariaceae (Pennycook & Galloway 2004).
