Phytologia 28, 5: 481 (1974).

Basionym: Parmelia viridescens Lynge, Ark. Bot. 13 (no. 13): 117 (1914).

Type: Brazil, Mato Grosso, Santa Anna da Chapada, G. Malme 2453 (S - lectotype; W - isolectotype).

Thallus: closely adnate, corticolous, pale buffor olivaceous ashy, 3-5 cm broad;lobes sublinear, contiguous to imbricate, 1-2 mm wide, the marginal bulbatecilic distinct, round, becoming apicallyciliate; upper surface shiny, plane ti distinctly rugulose, becoming heavily pycnidiate; lower surface dark brown or blackening, moderately rhizinate, the rhizines pale brown or darkening, simple or branched. Apothecia numerous, sessile to substipitate, the amphitecium and rim pycnidiate; spores 8, 4 X 6 µm.

Chemistry: Cortex K+ yellow, medulla negative with color tests, atranorin only present.

Ecology:

Molecular data:

Distribution: This is one of the few species of Bulbothrix lacking any medullary substances. It is a rare lichen with a limited range in Brazil and Uruguay but with more careful collecting should eventually be found in adjacent countries.