Myxotaxon 63: 49 (1997).
Type locality coordinates: 19°22'S, 43°32'W.
Type locality photo: Data lacking.
Type scan: Data lacking.
Molecular barcode: Data lacking.
Thallus: foliose, grey, loosely attached to the substate, up to 10 cm across. Lobes subirregular, elongate with rounded apices, 7-15 mm wide, 10-25 mm long, with ciliate margins; cilia up to 0.5 mm long. Upper surface faintly maculated. Medulla white. Lower surface black, dark brown below the apices of the lobes, densely rhizinate to the margins in some young lobes or a bare to papillate zone present at the apices, commonly erhizinate to the centre, rhizines concolorous, mainly simple. Apothecia up to 5 mm diam., disc brown, perforate, margin and thalline exciple smooth; asci clavate, 8-spored, ascospores hyaline, ellipsoid, 10-11x14.5-16 µm. Pycnidia laminal, immersed, mostly grouped in submarginal areas; conidia short filiform, 6.5-7 µm long (Eliasaro & Adler 1997).
Photobiont: Data lacking.
Chemistry: Upper cortex K+ yellow (atranorin, major). Medulla K+ yellow turning red (salazinic acid, major), C-, KC-, UV+ bright yellow (lichexanthone, major) (Eliasaro & Adler 1997).
Ecology: Saxicolous.
Distribution type: Known from the type only.
Taxonomy: This species is closely related to the isidiate Parmotrema ultralucens (Krog) Hale (Krog, 1974, Hale 1974, Krog et al. 1981, Elix 1994) which also contains salazinic acid and lichexanthone in the medulla and atranorin in the upper cortex. The main taxonomic difference between the species is the absence of isidia in Parmotrema lichexanthonicum. The species is also distinguished by the presence of apothecial perforations, a smooth exciple and faint maculation on the upper surface. In spite of these minor differences it could well be considered the parent species of Parmotrema ultralucens.
Note:
Consortium of North American Lichen Herbaria
Lichens of the Pacific Northwest