Oidium is a genus of Deuteromycetes, where traditionally most anamorphs of the order Erysiphales are included. Most of them are plant pathogens causing different forms of powdery mildew, for example:
Oidium alphitoides (= O. quercinum) = Microsphaera alphitoides (on oaks)Oidium anacardii (= Acrosporium anacardii) (on cashew)Oidium arachidis (on peanut)Oidium asteris-punicei (= Erysiphe cichoracearum) (on mangos)Oidium balsamii = Erysiphe verbasci (on mulleins)Oidium begoniae (=O.cyclaminis, O.lini, O.violae) = Erysiphe polyphaga (on Valerianella, Calluna and Erica)Oidium candicans (= Monilia candicans)Oidium caricae (on papayas)Oidium caricae-papayae (on papayas)Oidium caricicola (on papayas)Oidium chrysanthemi = Erysiphe cichoracearum (on numerous plant species, especially Asteraceae)Oidium carpiniOidium chartarum (= Torula chartarum)Oidium cyparissiae (= Acrosporium cyparissiae) (on cypress)Oidium erysiphoides = Sphaerotheca fuliginea (on melons, watermelons and cucumbers)Oidium euonymi-japonicae (on spindle-trees)Oidium farinosum = Podosphaera leucotricha (on apples)Oidium fructigenum = Monilia fructigena (on Rosaceae)Oidium helichrysi (on strawflowers)Oidium heveae (on rubber tree)Oidium hortensiae = Microsphaera polonica (on bear's breeches and hydrangea)Oidium indicum (on papayas and other tropical fruits)Oidium lauracearum (on laurel)Oidium lini ( = Euoidium lini)(on flax)Oidium lycopersicum (on tomatoes)Oidium mangiferaeOidium manihotisOidium monilioides (=O.tritici)= Blumeria graminis (on cereals)Oidium neolycopersici (on tomatoes)Oidium oxalidis = Microsphaera russellii (on sorrels)Oidium papayae (on papayas)Oidium pullorumOidium sesamiOidium tingitaninumOidium tuckeri = Uncinula necator (on grapes)Oidium albicans has been a parallel name of the yeast Candida albicans (not related to the powdery mildew).
Some other species of medical importance previously classified as Oidium include:
Oidium cutaneum = Trichosporon cutaneum (cause of some human fungal diseases)Oidium lactis (=Oidium pulmoneum) = Geotrichum candidum (in soil, water and air, also belongs to normal human flora)
