Bilimbia De
=MYXOBILIMBIA Hafellner, 2001
Type : Bilimbia hexamera De Not. [=Bilimbia sabuletorum (Schreb.) Arnold]
Type : Myxobilimbia lobulata (Sommerf.) Hafellner [=Lecidea lobulata Sommerf.]
Description : Thallus crustose or effigurate. Photobiont green, Trebouxia -like. Ascomata apothecia, biatorine or lecideine, with a prominent proper margin at first, soon disappearing and becoming convex, immarginate at maturity. Hamathecium of branched and anastomosing paraphyses. Asci with an apical tholus I+ blue, comprising a conical central body and a distinct, amyloid, tube-structure. Ascospores, colourless, transversely septate, with a thickened, wrinkled or warted perispore (easily detached and often overlooked).
Key
Bilimbia is included in the Lecanorales incertae sedis (Eriksson et al. 2004; Pennycook & Galloway 2004). It was recently reinstated (Veldkamp 2004) to accommodate four species of the Bacidia sabuletorum group previously included in Myxobilimbia (Hafellner & Türk 2001). Following Ekman (1996a: 46), species of the B. sabuletorum group are distinguished from the closely related genera Biatora and Mycobilimbia by having "a more heavily pigmented hypothecium, stouter paraphyses, more thick-walled asci, an oily yellowish content in the mature spores, a green pigment in the upper part of the hymenium, and in having a proper exciple, the rim of which is covered by a rather thick gelatinous layer that swells markedly (and finally almost dissolves) in K [and] a warted perispore (although sometimes overlooked, since it is easily detached from the spores)". Differences in the colour of the epithecium and hymenium, tholus type, ascospores size and shape, and habitat are also useful distinguishing characters (Sarrión et al. 2003). Two species of Bilimbia are known from New Zealand.
