Grayish spores of downy mildew, Peronospora farinosa, on the underside of a spinach leaf with yellowish discoloration caused by the plant-pathogenic oomycete.
Grayish spores of downy mildew, Peronospora farinosa, on the underside of a spinach leaf with yellowish discoloration caused by the plant-pathogenic oomycete. Credit: unknown photographer
