Flora of New Zealand Series

Thallus foliose, dorsiventral, heteromerous, lobate, greenish-yellow, brownish-red or greyish-brown, or ± greyish in sheltered situations, usually quite thin, 100-300 µm thick, spreading, 2-30 cm diam., corticolous or saxicolous. Upper surface corticate, smooth, wrinkled or faveolate-impressed, matt or shining, sometimes ± maculate, isidia or phyllidia present or absent, soredia and pseudocyphellae absent. Photobiont green (Coccomyxa) or blue-green (Nostoc) in a layer 30-60 µm thick, green photobiont species often have internal cephalodia of blue-green algae present towards the lower surface. Medulla white, of loosely woven hyphae, 40-260 µm thick. Lower surface corticate, black or pale brown or whitish, bullate, or smooth and ± undulate. Apothecia non-emergent, on lower surface at apices of lobes, discs red-brown or light to dark brown. Ascospores 8 per ascus, 1- to 3-septate, pale brown.

Nephroma included in the family Peltigeraceae, comprises c. 30 species distributed in the temperate zones of both Northern and Southern Hemispheres. Although no recent monograph is available, the study of North American species [Wetmore Publs Mich. St. Univ. Mus. biol. ser. 1 (11): 369-452 (1960)] contains useful information. Some New Zealand species and their synonyms are discussed by Murray [ T.R.S.N.Z. (Bot.) 88: 381-387 (1960)]. In the present account 6 species are recognised in New Zealand, all characteristic of moist, humid habitats.