Pyrenomycetes Species Page

Acanthonitschkea tristis

Small clustered ascomata
(Pers.) Nannf., Svensk bot. Tidskr. 69(1): 57 (1975)
Sphaeria tristis Pers.
Figure from SMH4723 (Ecuador)
Genbank Accession: FJ968949 (LSU), FJ969043 (tef1)
Complete Description
Ascomata turbinate, collapsing collabent when dry, dark brown to black, 310-385 µm diam., 200-250 µm high, superficial, with a tuberculate surface,occurring densely clustered on abundant, setose, subicular hyphae. Subiculum extensive, forming large and dense patches, hyphae brown to black, wide, septate, dichotomously branched, distinctly spinulose with long, tapering, non-septate, pointed setae, most abundant around the ascomatal base. Ascomatal wall of textura globosa in surface view, composed of pale brown, pseudoparenchymatic cells; Munk pores present, few per cell. Ascomatal apex collabent, with an indistinct ostiole. Centrum composed of a small apical cushion of thin-walled cells with a central canal opening lined with periphysis-like cells, quellkorper absent, paraphyses absent. Asci clavate, long stipitate, spore bearing part 40-50 x 8-10 µm, pedicels 30-40 µm long, without a distinct apical ring, with eight biseriately arranged ascospores. Ascospores subcylindrical to ellipsoid, hyaline, one septate, generally with two large guttules, 6-7 x 2-3 µm.
Found on decaying wood and bark. Our only collection is from Ecuador. The type is from Sweden. Because of the confusion in correctly applying this name, Nannfeldt (1975) restricted this species to only specimens that he had looked at thus restricting its distribution to Europe.
Similar Taxa Comments
Despite Nannfeldt’s (1975) restricted distribution of this species to Europe based on his own observations, we apply this name because this specimen matches Nannfeldt’s species concept and description. It is distinguished from A. argentinensis by subcylindrically shaped ascospores and abundant subicular setae surrounding the ascomatal base, and not present on the surface of the ascoma. The ascospore measurments of this specimen from Ecuador are slightly wider than those given by Nannfeldt (1975).
Nannfeldt 1975