Key Number 2, Fungal Spores

Large, dark cigar-shaped spores

• Generally straight and uniformly dark

  (Drechslera spp.)

• Generally curved, sometimes with "keystone" cell; end cells lighter than center cells

  (Curvularia spp)

Slender, crecent-shaped spores

• Two or more cells; dark acervuli with black spines NOT PRESENT on infected leaves and stem-bases

  (Microdochium nivale)

• Generally one cell, crescent shape with hole in center; dark acervuli with black spines PRESENT on infected leaves or stem bases

  (Colletotrichum graminicola)

  *during hot weather

  *during cool weather