Family: Icmadophilaceae |
Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1. Life habit: lichenized Primary thallus: crustose, smooth and continuous (to indistinct or within the substrate) to rimose-areolate, areolate, verrucose or granular, thin to thick (up to 1 mm), pseudocorticate surface: chalky white (when calcium oxalate crystals present), pale gray, beige, or greenish, continuous or rimose; soredia, schizidia or isidia-like tubercles sometimes present photobiont: primary one a chlorococcoid alga, secondary photobiont absent Secondary thallus: podetia sometimes present, arising laminally on the primariy thallus, short (mostly under 2 cm tall), erect, usually unbranched, ± hollow Ascomata: apothecial, up to 4-7 mm diam., usually occurring on podetia, without a thalline margin; disc: roundish, pink to almost white, plane or soon swollen (dome-shaped to partly irregularly folded, or spherical); proper margin: not or slightly prominent; true exciple: hyaline, not distinct from the interior of the stipe; hymenium gel: I+ blue; paraphyses: not branched or anastomosing, little thickened above; hypothecium: hyaline asci: cylindrical, thin-walled, unitunicate, with a thin, K/I+ blue apical cap, (4-) 8-spored ascospores: mainly simple (occasionally indistinctly 1-3-septate), cylindrical-ellipsoid, fusiform, or citriform, obtuse or apiculate at the poles, c. 7-24 (-30) x (2-) 2.7-5 (-8) µm, wall hyaline, smooth or halonate with multilayered appendages, without distinctly developed endospore thickening, I- Conidiomata: pycnidial, immersed in warts, laminal to lateral conidia: short bacilliform, formed pleurogenously Secondary metabolites: thallus, stipes and apothecia with ß-orcinol depsides Geography: mostly tropical to subtropical in both hemispheres, and one species (D. baeomyces) holarctic and temperate Substrate: on soil, detritus or non-calciferous, siliceous rock. Notes: Dibaesis is segregated from Baeomyces on the basis of such characters as apothecial color, amyloidy of the hymenium, ascus type and secondary chemistry (depsides rather than depsidones). Dibaeis is divided into two subgenera: subg. Dibaeis with stalked, clavate to capitate (domed to spherical) apothecia, fusiform to aciculate ascospores and nonlichenized to lichenized stipes, and subg. Apoda with flat, sessile or stalked apothecia, ellipsoid ascospores, and mostly non-lichenized stipes. The subg. Apoda, which includes D. absoluta, is also characterized by a poorly developed horizontal thallus, simple ascospores, and asci showing only weak tendencies of reduction of the amyloid ring. Rambold et al. (1993) placed Dibaeis in a new family Icmadophilaceae, while Tehler (1996) didnt mention Dibaeis but treated Baeomyces and Icmadophila under the family Baeomycetaceae. |