Peltularia R.Sant.
Thallus foliose, heteromerous, dorsiventral, attached to substrate by a ± central umbilicus or by several disc-like holdfasts, saxicolous. Lobes undulate to ± folded, monophyllous or ± polyphyllous, margins entire, incised or ± crenulate, with or without soralia. Upper surface ± areolate or scabrid, rarely smooth with or without soralia. Photobiont blue-green, Nostoc or Scytonema. Medulla white. Lower surface pale, whitish to yellowish-brown, thinly tomentose or ± glabrous, smooth to ± faveolate-lacunose. Apothecia hemiangiocarpic, ± immersed to subsessile or urceolate, rounded, thalline margin present or absent, concolorous with thallus. Hymenium 65-100(-120) µm tall, I+ blue, colourless, with a pale brown or brown epithecium. Paraphyses simple, septate, 2 µm thick, apices slightly capitate, with brown pigment external to cells. Asci broadly clavate, with external amyloid cap, 8-spored. Ascospores colourless, thin-walled, ellipsoid to ± spherical, simple to 2(-3)-septate. Pycnidia not seen.
Peltularia, formerly thought to be a monotypic Patagonian genus in the family Heppiaceae Santesson Ark. Bot. 31A (7): 1-4 (1944) is now known to contain two species and is apparently related to Steinera and placed in the family Coccocarpiaceae [Jørgensen and Galloway Lichenologist 16: 189-196 (1984)]. One species is known from alpine rocks on Campbell and Macquarie Is.