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Dactylospora athallina (Mull. Arg.) Hafellner
Family: Dactylosporaceae
[Buellia athallina Müll. Arg.,  more]
Dactylospora athallina image
Apothecia: black, +round, semi-immersed to sessile, 0.3-0.8 mm in diam., with thin but distinct margin exciple: dark brown to reddish brown, 25-35 µm thick, in the lower part composed of subglobose to ellipsoid cells 4-8 µm in diam., marginally cells arranged in rows and smaller hymenium: hyaline to pale yellow, the uppermost part red-brown, 60-70 µm tall paraphyses: 1.8-2.2 µm wide, in the upper part with some ramifications, with enlarged tips provided with red-brown pigment caps, embedded in a concolorous gelatinous matrix, with epihymenial pigment reacting with K dissolving in a purple solution hypothecium: pale brown to ochre, 30-60 µm thick, composed of short-celled interwoven hyphae asci: cylindrical to sub-clavate, 35-45 x 10-13 µm, 8-spored ascospores: brown, 1-septate, 9-14.5 x 4-7 µm, with cells of +equal size; wall: relatively thin, sometimes slightly constricted at the septum Conidiomata: not observed. Hosts: Baeomyces rufus; hosts known outside the Sonoran region: Baeomyces heteromorphus; on the thallus; commensalic, the infested host thalli not significantly damaged World distribution: widely distributed in Europe, also known from North America (U.S.A., Canada), and Australia Sonoran distribution: so far known from a single locality in eastern Arizona. Notes: Only one further Dactylospora, D. purpurascens Triebel, contains similar epihymenial pigments, but that species is easily distinguished by its larger ascospores and its host selection (preferably on Porpidiaceae).