Flora of New Zealand Series

Type : Hypotrachyna brasiliana (Nyl.) Hale [=Parmelia brasiliana Nyl.]

Description : Thallus foliose, dorsiventral, loosely to tightly adnate. Lobes sublinear or rarely subirregular or linear–elongate, 0.5–6 mm wide; margins eciliate; apices truncate, incised or rarely subrotund, sinuses often semi-circular. Upper surface whitish to grey (atranorin or lichexanthone) or yellow-green (usnic acid), with or without maculae, soredia, pustules and isidia, without pseudocyphellae; with palisade cortex and pored epicortex. Cell walls containing isolichenan. Medulla white or occasionally partly yellow or orange. Lower surface black, sometimes paler towards lobe apices, rhizinate to lobe margins; rhizines black, dichotomously branched, rarely squarrosely branched in part, conspicuously projecting beyond margins. Ascomata apothecia, laminal, sessile to subpedicellate, 1–10 mm wide; disc imperforate. Ascospores ellipsoidal, 8 per ascus, 6–16 × 3–10 μm. Conidiomata pycnidia, immersed, laminal. Conidia bifusiform, 5–8 × 1 μm.

Hypotrachyna, included in the family Parmeliaceae (Eriksson et al. 2004: Pennycook & Galloway 2004), comprises some 165 species worldwide (Hale 1975, Awasthi 1976; Krog & Swinscow 1979, 1987; Elix 1994h; Kurokawa & Moon 2000; Kurokawa & Lai 2001; Kantvilas et al. 2002; Louwhoff & Elix 2002a; Nash et al. 2002b; Schumm 2003). Species are characterised by the absence of marginal cilia, dichotomously branched rhizines on the lower surface, a pored epicortex and irregular, sublinear to linear lobes. The genus is widespread in both temperate and tropical regions with major areas of speciation in both the American and Asian tropics (see above). Recent molecular sequence data for species of Hypotrachyna indicate that the genus is polyphyletic, and additional phylogenetic studies are in progress to resolve this (Blanco et al. 2004a). Fifteen species are here recorded from New Zealand.