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Family: PleomassariaceaeGenus: Asteromassaria
Anamorph: a Phoma-like microconidial state is known from culture (Tanaka et al. 2005).
Teleomorph: ascostromata perithecial, 650-800 µm diam. and 250-350 µm high, oblate to oblate-conical, scattered or in small clusters of 2-5, initially immersed within the host epidermis but becoming partially erumpent, the ostiole central. Ascostromatal wall 50-90 µm thick laterally, 35-60 µm thick around the ostiolar region and only 5-10 µm thick at the base of the ascostroma, composed of layers of elongate to angular dark brown cells. Interascal tissue of narrow pseudoparaphyses, 1-2 µm diam., septate, branched and anastomosed, developing within a gelatinous matrix. Asci 250-270 x 55-71 µm, clavate, very thick-walled, fissitunicate, with a short tapering base and a rounded apex with a conspicuous ocular chamber, not staining blue in iodine, 8-spored. Ascospores arranged biseriately, (52-) 56-74 x 21-26 µm, broadly fusiform to fusiform-ellipsoidal, the ends obtuse to rounded, often slightly curved, with a constricted median to slightly submedian primary septum, sometimes eventually developing further septa close to the apices of the spore, very thick-walled, hyaline and smooth-walled, surrounded by a very conspicuous gelatinous sheath 2-5 µm thick within the ascus, expanding greatly after discharge. Senescent ascospores are usually 3-septate, golden to mid brown, irregularly shrunken and with a minutely echinulate surface.