Appendages coiled or hooked at tip - Uncinula
Appendages simple and straight with bulb-like base - Phyllactinia
Appendages branching dichotomously (antler-like at tip)
Cleistothecium contains a single ascus - Podosphaera
Cleistothecium contains several asci - Microsphaera
Appendages simple or irregularly branched, often entangled
Cleistothecium contains a single ascus - Sphaerotheca
Cleistothecium contains several asci - Erysiphe
Key to Genera of Powdery Mildew
(Drawing courtesy of C.B. Kenaga, E.B. Williams, and R.J. Green)
