Lambiella Hertel
Beih. Nova Hedwigia, 79: 459, 1984.
Systematics:
Phylum: Ascomycota Caval.-Sm.
Subphylum: Pezizomycotina O.E.Erikss. & Winka
Class: Lecanoromycetes O.E.Erikss. & Winka
Subclass: Ostropomycetidae Reeb, Lutzoni & Cl.Roux
Order: Trapeliales B.P.Hodk. & Lendemer
Family: Xylographaceae Tuck.
Brief description: Thallus crustose or absent in non-lichenized species, grey, brownish or black. Apothecia lecideine, black, often gyrose, with a persistent proper margin. Proper exciple thin, dark brown; epithecium greenish to brown; hymenium colourless or greenish in lower part; paraphyses branched and anastomosing, usually moniliform in upper part; hypothecium mostly brownish. Asci 8-spored, broadly clavate, with a K/I+ blue tholus with a funnel-shaped central unstained region and a small, obconical, apical K/I+ blue dome, Lambiella-type. Ascospores 1-celled, hyaline (rarely turning brownish when overmature), broadly ellipsoid to ovoid,. Pycnidia brown to black. Conidia simple, hyaline, bacilliform. Photobiont chlorococcoid or absent. Chemistry: lichenized species mostly with stictic and/or norstictic acid, one species with gyrophoric acid.
Note: This genus of the Xylographaceae (Resl & al. 2015) was established as monotypic for L. psephota (Hertel 1984), formerly treated as a Rimularia. A recent molecular study of several trapelioid genera by Resl & al. (2015) revealed the polyphyly of Rimularia, and brought to an expanded definition of Lambiella, which at the moment includes c. 28 species. It differs from Rimularia in molecular characters, in the presence of depsidones, and perhaps in the apical apparatus of the asci. The genus is closely related to Lithographa; the only character separating the two genera being the shape of the ascomata (Spribille & al. 2014). Some species were segregated by Kondratyuk & al. (2022) into the new genus Brianiopsis which, pending further study, is not accepted here.
Type: Lambiella psephota (Tuck.) Hertel
