Flora of New Zealand Series

Thallus small-foliose, lobate, dorsiventral, heteromerous, attached to substrate by clumps of rhizines. Upper surface ± hairy or tomentose, the tomentum white or yellowish or brownish-buff. Photobiont blue-green, Scytonema. Lower surface white or yellowish-brown, strongly tomentose. Rhizines black, often in thick separate clumps or tufts. Apothecia ± marginal, sessile or subpedicellate with a well-defined thalline margin and exciple. Ascospores 8 per ascus, colourless, simple, ellipsoid or elongate-fusiform. Pycnidia marginal, brown or black. Conidia of Sticta -type, septate, short, cylindrical.

Erioderma included in the family Pannariaceae, contains c. 22 described species [Keuck, Biblthca lich. 6: 1-175 (1977)]. The genus is best developed in the tropics although in strongly oceanic environments species penetrate as far north as Scandinavia and as far south as Patagonia. Two species recorded from New Zealand [Galloway and Jørgensen Lichenologist 7: 139-142 (1975)] are characteristic of successional vegetation in humid habitats.