Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: crustose, poorly developed, thin, sometimes nearly absent, compact to verruculose or granular-pulverulent or minutely coralloid, often minutely wrinkled when dry (x 50) granules: 25-100 µm in diam. surface: brown or black-brown to dark greenish brown, rarely reddish brown, dark green to dark brown when wet Apothecia: usually abundant, often coalescing, sessile or immersed among verrucules, 0.12-0.3(-0.5) mm in diam. disc: pinkish to dark reddish brown (rarely black), plane but soon convex; rough, dull margin: soon excluded exciple: thin, persistent or usually soon disappearing, +pseudoparenchymatous, with cells 9-15 x 8-10 µm epihymenium: brown hymenium: pale to dark brown or streaked with brown, 60-85 µm tall, I+ reddish orange; paraphyses: indistinct, 12 µm wide below, richly branched, with thickened tips up to 5-6 µm wide above and often brown-capitate; hypothecium: dark brown to mostly brown-black, paler above, K-, I+ orange asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, (7-)8-14(-16.5) x (4-)5-6(-7) µm Spot tests: thallus K-, C-, KC-, P-, I- Secondary metabolites: none detected. Substrate and ecology: on acidic or peaty soil in open areas, also often on dead bark and wood of fallen trees and stumps, occasionally on bare sandy soil World distribution: circumpolar arctic to northern temperate, subcosmopolitan Sonoran distribution: Arizona and southern California. Notes: Placynthiella uliginosa is characterized by its C-, subgelatinous, non-coralloid, granular thallus, and its numerous, concolorous, soon convex, apothecia. It resembles P. oligotropha except that the granules are much smaller (less than 150 µm in diam.), appearing almost farinose.