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Family: MetacapnodiaceaeGenus: Metacapnodium
Colonies composed of an extensive mat of intertwined hyphae, olivaceous brown to black, superticial, effuse, flat to irregularly thickened, 3-8 mm thick (-20 mm fide Hughes1981), sometimes forming separate pustules that become extensive by confluence. Mycelium composed of brown to dark brown anastomosing septate strongly moniliform hyphae which taper markedly toward their apices. Hyphae straight or curved with upwardly curved branches originating at right angles, smooth to finely roughened throughout and usually warted towards the apices. Cells about as broad as or broader than long, doliiform and 22-27 µm diam. in the central part, tapering to ca 8.5 µm diam. at the apices.
Conidiogenous cells in clusters on the ends of usually robust but otherwise undifferentiated hyphae 140-280 µm long and on short solitary or crowded, mostly unilateral subterminal branches; usually unilaterally on the penultimate cell and on one or two cells below this cell; subglobose and usually coarsely warted through irregular fragmentation of an outer wall during conidium production. Terminal conidiogenous cells hemispherical to doliiform, to 12.5 µm dia. and to 14.5 µm long, lateral conidiogenous cells shorter and 6.3-8 µm diam.: at maturity they bear scars on very short denticles at the distal end after schizolytic conidium secession. Conidia mostly 24-27 x 9-12.5 µm, produced blastically on successive new growing points: they are dry, ovoid to obclavate, mostly 2-septate (shorter when 1-septate and longer with more septa), slightly constricted at the septa, thick-walled, very coarsely warted, pale brown to dark brown with the basal cell bearing a circular scar.
Ascostromata perithecial, partly immersed in the mycelium, crowded or scattered, brown to dark brown, ellipsoidal, 140-225 µm high and 120-185 µm diam., ostiolate, the wall with unbranched moniliform appendages to 60 µm long in the ostiolar region. Asci 57-72 x 18-22 µm, ellipsoidal to obclavate, fissitunicate, 8-spored. Ascospores irregularly biseriate, 20-25(-27) x 9-10 (-11) µm , ellipsoidal, sometimes inequilateral, brown to dark brown, 3-septate, scarcely constricted at the septa, thick-walled, without paler thinner-walled areas.
Description adapted from Hughes (1981).