Flora of New Zealand Series

Thallus dimorphic. Primary thallus small, verrucose, soon disappearing. Secondary thallus of persistent, fruticose, often richly branching pseudopodetia, firmly attached to substrate by a stout holdfast; pseudopodetia with inconspicuous cephalodia (containing Nostoc), and with ± scattered phyllocladia. Photobiont green, ? Trebouxia. Apothecia terminal, often large, expanded, to twice as wide as supporting branch or wider, disc plane with a prominent margin, exciple massive, cupuliform, coarsely wrinkled-scabrid. Ascospores large, muriform, 1-2(-6) per ascus, broadly cylindrical-ellipsoid. Pycnidia sometimes present, below apothecia, minute, swollen, clustered, ostiole punctate, black. Conidia filiform, curved.

Argopsis is a Southern Hemisphere genus of three species [Lamb J. Hattori bot. Lab. 38: 447-462 (1974)] which are restricted to the Auckland, Campbell and Crozet Is and to Kerguelen. The genus is related to Stereocaulon and is included in the family Stereocaulaceae [Jahns Beih. Nova Hedwigia 20: 38-40 (1970); Lamb loc. cit. , Galloway Bot. Notiser 133: 261-279 (1980)].

One species is known from the New Zealand botanical region, and occurs in the Auckland and Campbell Is.