Phylum. Oomycota
Order: Peronosporales (Downy mildews)
This group contains the most advanced Oomycota. They are mostly obligate parasites on the aerial parts of higher plants. This order contains many destructive parasites of economic plants, and causes tremendous losses in crops each year. Since their spores are wind borne, their sporangia are not unspecialized hyphal tips, but borne on branched aerial asexual "sporangiophores", which produce asexual spores,There are also sexual sporangia borne on"sporangiaophores".
Albuginaceae:
Albugo candida:
Otherwise known as a "white rust" (cause White rust of crucifers)
Pythiaceae
Peronosporaceae
Peronospora parasitica: