Flora of New Zealand Series

Type : Lobothallia alphoplaca (Wahlenb. in Ach.) Hafellner [=Parmelia alphoplaca Wahlenb. in Ach.]

Description : Thallus crustose, tightly to loosely adnate, placodioid with radiating marginal lobes, ±crustose–areolate centrally, chalky white, brownish or greyish. Photobiont green, chlorococcoid. Medulla I−. Ascomata apothecia, aspicilioid (cryptolecanorine), subimmersed to sessile. Thalline exciple ±well-developed and persistent. Disc plane to subconcave, dark red-brown to brown-black, ±pruinose. Epithecial pigments greyish brown, not green, N–, K−. Hymenium colourless, to 100 μm tall, I+ blue. Hypothecium colourless to very pale brownish. Hamathecium of simple, unbranched paraphyses which are never moniliform. Asci narrowly clavate to cylindrical, apices I− or weakly I+ bluish, 8-spored. Ascospores simple, ellipsoidal to globose, colourless, thin-walled. Conidiomata pycnidia, immersed, flask-shaped to subglobose. Conidia acrogenous, simple, colourless, bacillar.

Lobothallia, first proposed as a subgenus of Aspicilia (Clauzade & Roux 1984), was raised to generic rank by Hafellner (1991) to accommodate taxa in the Aspicilia radiosa -group (Hermann et al. 1973; Ryan 2004a). Taxa are characterised by brownish, greyish or whitish rosette-forming thalli with characteristic, radiating plicate–lobate margins, a lack of cortical pigments, a frequent K+ red reaction (norstictic acid), immersed to adnate, cryptolecanorine (aspicilioid) apothecia, and non-amyloid asci (Ryan & Nash 1997: 407). It lacks the moniliform paraphyses and N+ green epithecial pigments found in Aspicilia (q.v.). The genus is included in the family Hymeneliaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) and comprises five species. Nomenclatural notes on the genus are given in Ryan & Nash (1997: 406–408). One species is known from New Zealand.