Flora of New Zealand Series

Type : Dermatocarpon miniatum (L.) W.Mann [=Lichen miniatus L.].

Description : Thallus foliose, heteromerous, attached to substratum by a ±central umbilicus or holdfast; without rhizohyphae or rhizines. Upper surface ±finely scabrid to dull, grey to dark-brown, ±whitish-pruinose, mainly smooth but with slightly raised or papillate spots of ostioles of ascomata or conidiomata. Lower surface smooth, verrucose or veined, without tomentum. Upper cortex pseudoparenchymatous, gells ±globose. Lower cortex, of several rows of pachydermatous cells (of Dermatocarpon -type). Photobiont green, chlorococcoid. Medulla of thin, filamentous hyphae. Ascomata perithecia, laminal, completely immersed in thallus, uniloculate, globose. Involucrellum absent. Exciple hyaline. Hamathecium of periphyses. Asci bitunicate, 8-spored, cylindrical–clavate to saccate, thick-walled, Verrucaria -type; apical dome distinct in young asci and with an ocular chamber, but becoming reduced and ±absent in mature asci. Ascospores simple, globose to narrowly ellipsoidal or ovoid, colourless, smooth, without a perispore. Conidiomata pycnidia, immersed, similar in size to perithecia, wall colourless. Conidia bacilliform, simple, colourless. Chemistry : TLC−.

Dermatocarpon, included in the family Verrucariaceae (Eriksson et al. 2004; Pennycook & Galloway 2004), is the sole foliose member of that family and is a genus of wide distribution, comprising c. 35 species (Glavich & Geiser 2004; Heiðmarsson & Breuss 2004) found mainly on damp rocks (acid and basic) by streams, rivers or lakes. Its taxonomic history is discussed by Harada (1993a), and a recent revision (Heiðmarsson 2001) details 10 species from Scandinavia and provides an excellent modern account of the genus. A molecular study of D. miniatum (the generitype) and allied taxa is recorded in Heiðmarsson (2003). New Zealand taxa formerly included in Dermatocarpon (Galloway 1985a: 155–157) are now placed in Catapyrenium (q.v.). Species of Catapyrenium and Placidium are distinguished from Dermatocarpon by having a lower surface with numerous rhizines or rhizohyphae. One species is recorded from New Zealand.