Two new genera in the Phyllachoraceae: Sphaerodothella to accommodate Sphaerodothis danthoniae, and Parberya gen nov

Abstract

Sphaerodothis danthoniae produces black tar spots on leaves and culms of Danthonia spp. It is redescribed and illustrated in a new genus Sphaerodothella. Sphaerodothella danthoniae differs from Sphaerodothis in having a peridium composed of hyaline to brown, thin-walled, flattened fungal cells which merge with host cells, rather than a distinct stroma of melanised textura globosa, and pale brown ascospores which have a distinctive dark brown mucilaginous perisporium. Parberya is described for a new species of tar spot fungi, P. kosciuskoa, found on Danthonia pallida from Mt. Kosciusko, Australia, and to accommodate Sphaerodothis arxii P.F. Cannon on Pentameris sp. Parberya are typical phyllachoraceous tar spot fungi on grasses, which have distinctive golden-brown ascospores ornamented with short, blunt spines. The previously undescribed andromorph of Parberya arxii is also described.