Lepra monogona

Like Lepra excludens, but soralia and isidia absent and fertile. Fertile warts numerous, arising from low tubercles, ± elevated, becoming 1.5–2.5 mm diam. Apothecia 1-4 (- 6) per wart, deeply immersed; disc flat, ± veiled, ± black, coarsely white-pruinose, surrounded by an irregular, often smooth and raised thalline exciple, the inner edge somewhat torn; epihymenium with numerous crystals, K–. Asci 1-spored, often aborting. Ascospores 100–300 × 50–100 μm, wall relatively thin (4–5 μm), not striate or zoned. Thallus reactions and chemistry as in P. excludens: medual C–, K+ yellow→blood-red, KC+ yellow-red, Pd+ yellow-orange, UV± pale grey or grey- yellow, (norstictic, ± salazinic, ± unknown fatty acids, ± UV+ yellow xanthone). 

Characterised by the fertile warts in which apothecia are immersed with white pruinose discs and by the K+ red thallus. The broad thick-margined rounded apothecia with an irregular ± pruinose opening and veiled disc are also diagnostic; they are usually paler than the thallus. Lepra monogona is possibly the fertile counterpart of  L. excludens, but the former taxon has not been sequenced.