TYPE. “No relevant material [of Lichen gracilis L.] in LINN, but can be typified in this sense with a specimen in Herb. Dillenius (OXF); comm. P.W. James” (Ahti 1980).
Description. Lichenized fungus.
Thallus dimorphic to fruticose. Primary thallus squamulose, disappearing. Podetia slender, 2-10 cm tall, 0.2-2 mm thick, greenish gray to dark brown, usually unbranched, tips usually pointed without cups; cups when present narrow, 1-3 mm diam., 0-5 per podetium, margins toothed; base somewhat squamulose and darkened brown to blackish. Podetial surface corticate, areolate with ecorticate spaces brown or whitish. Photobiont Asterochloris alga. Ascomata biatorine apothecia, frequent, brown, 1-3 mm diam., on cup margins; ascospores narrowly ovoid, 10-15 x 2.5-3.5 μm. Pycnidia on cup margins; conidia fusiform, straight or curved, 6-10 x 0.5-1 μm.