Hypotrachyna Lichen

Hypotrachyna dentella

Parmelia dentella Hale and Kurokawa, 1964:172. [Type collection: Cheaha State Park, Clay County, Alabama, McCullough 570 (US, holotype; TNS, isotype).]

Parmelia laevigata var. ceratina Müller Argau, 1880:267. [Type collection: Petrópolis, Brazil, Deventer (G, lectotype).]

Thallus loosely adnate on rocks, 3–8 cm broad, greenish mineral gray; lobes subirregular to linear, short, 2–6 mm wide; upper surface plane, continuous, often quite white-maculate, densely isidiate, the isidia simple to branched, up to 0.7 mm high; lower surface sparsely to moderately rhizinate, the rhizines sparsely dichotomously branched. Apothecia rare, adnate, 1–2 mm in diameter; spores 4μ–6μ × 8μ–10μ.

CHEMISTRY.—Cortex K+ yellow, medulla K+ yellow, C− or C+ pale yellow, P+ orange (atranorin, barbatic acid, echinocarpic acid, 4-O-demethylbarbatic acid, obtusatic acid, and norobtusatic acid).

DISTRIBUTION.—Southeastern United States, Mexico, Venezuela, and Brazil.

HABITAT.—On rocks in open woods and pastures at about 1000 m elevation.