PYRENOMYCETIDAE (or Hymenomycetidae--the Pyrenomycetes): asci borne in a layer; ascocarp a cleistothecium or a perithecium; contains Chaetomiales, Clavicipitales, Coronophorales, Diaportheales, Erysiphales, Hypocreales, Phyllachorales, Sordariales, and Xylariales

• Erysiphales ("the powdery mildews; the black mildews"): obligate parasites of higher plants
  • Young ascocoma are globose (thus often put with Plectomycetes) with the young asci borne in a layer.
    • Genera are differentited by the shape of the mycelial appendages which arise from the ascosoma and by the number of asci per ascoma

dichotomously branched mycelial appendages	mycelial appendages pointed; with bulbous base	myelial appendages coiled
Microsphaera	Phyllactinia	Uncinula

	several asci coming from two different ascoma.	several asci coming from two different ascoma.
	Phyllactinia	Uncinula