Flora of New Zealand Series

Type : Icmadophila aeruginosa (Scop.) Trevis. [=Lichen aeruginosus Scop =I. ericetorum (L.) Zahlbr.]. See also Imshaug (1972: 301); Jørgensen & Santesson (1993: 884); Rambold et al. (1993: 228–229); and Jørgensen et al. (1994a: 305).

Description : Thallus crustose to subsquamulose or distinctly squamulose to small-foliose. Photobiont green, of Coccomyxa -type. Ascomata apothecia, sessile to substipitate (podetia). Monokaryotic hyphal tissue ±unpigmented in various thallus layers. Exciple reduced or mainly built up by podetial hyphae. Hamathecium of paraphyses, simple or poorly branched, slightly thickened apically. Asci cylindrical. Ascospores colourless, ellipsoidal, fusiform–ellipsoidal, allantoid, simple to 3-septate. Spore walls mostly with bipolar gelatinous sheaths, not cyanophilic.

Icmadophila is the generitype of the family Icmadophilaceae (Rambold et al. 1993; Lizon et al. 1998; Johnston 2001c; Stenroos et al. 2002c; Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) in which also are included Dibaeis Clem., Endocena Cromb., Pseudobaeomyces M.Satô,  Siphula, Siphulella Kantvilas, Elix & P.James,  Thamnolia. Recently, Platt & Spatafora (1997) and Stenroos & De Priest (1998a) reported that the non-sexual Siphula showed strong affinity for the Leotiales and formed a monophyletic clade with the Icmadophilaceae in their analysis of SSU and LSU nuclear rDNA sequence data. Additional molecular studies confirm that Icmadophila and Dibaeis are remote from Baeomyces, and group within the Icmadophilaceae (Platt & Spatafora 1999, 2000), and Stenroos et al. (2002c) report that the genera Endocena, Siphula and Thamnolia are included within the Icmadophilaceae but that the status of Pseudobaeomyces and Siphulella (Johnston 2001d: 22–23) is presently unresolved. There are four species known in Icmadophila, only one of which is widely distributed. Species colonise acid substratums in cool to temperate humid climates, and are found mainly on decaying mosses, wood, soil or peat (Galloway & Elix 1981; Rambold et al. 1993). Two species are known from New Zealand. The monospecific genus Knightiella (Galloway & Elix 1981; Galloway 1985a: 202–203) was recently transferred to Icmadophila (Galloway 2000c).