Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Thallus: crustose, usually poorly developed and unapparent, never distinctly areolate, effuse surface: whitish gray to green-gray, not corticate Apothecia: sessile, 0.08-0.2(-0.25) mm in diam. disc: black, convex to sub-globose, epruinose proper exciple: not evident, even in young apothecia epihymenium: patchy brown, K+ olivaceous, N+ red hymenium: hyaline or with dark brown (K+ olivaceous) streaks, 30-50 µm tall; paraphyses: scanty, composed of two types, one type unbranched, 1.5-2 µm thick and the other branched and sometimes anastomosing, 0.8-1 µm wide, not capitate but sometimes widening to 1.8 µm; hypothecium: dark ±reddish brown, K- or K+ brown (losing red color), N+ pale red, upper part K+ olivaceous, N+ red, 60-95 µm thick asci: clavate, 28-36 x 9-12 µm, 8-spored ascospores: hyaline, simple, ellipsoid, (6-)7.5-10(11.5) x (3.2-)3.5-4.5(-4.8) µm Pycnidia: partly immersed to ±sessile, c. 60 µm in diam.; wall: brown (N+ pale red), olivaceous (N+ red) around the ostiole conidia: (microconidia) simple, bacilliform, (4-)4.5-5 x 0.8-1 µm Spot tests: K-, C-, KC-, P- Secondary metabolites: none detected by TLC. Substrate and ecology: usually on damp wood World distribution: western Europe (Great Britain, Belgium), Japan, Tasmania, and North America Sonoran distribution: one old Hasse collection from southern California (Santa Monica Mountains). Notes: Among the species reported from the Greater Sonoran Region, Micarea deminuta is most similar to M. misella, but that species has a K+ violet epihymenium, usually occurs on drier wood, and has stalked pycnidia. Other North American species, with which M. deminuta could be confused, are M. botryoides, which has broader ascospores and stalked pycnidia, and M. melaena, which has (1-)3-septate ascospores. This is a new record for North America.