Description:
rust
Spores: teliospores 2-celled, 13-19 x 30-67 µm, with 3-10 apical projections, chestnut brown wall; urediospores echinulate, 6-8 scattered pores; aeciospores hyaline, finely spiny; spermatia are on upper surface of buckthorn leaves, in groups.

Diagnostic macroscopic feature: distinguished by elongate aecial cups in rust spots on buckthorn leaves and stems; brownish-yellow pustules on grass species on both sides of leaves

Diagnostic microscopic feature: teliospores on grass species have apical prongs that are distinctive, and are referred to as a crown by the epithet coronata

Nutritional Mode: obligate parasite

Substrate: uredia, telia and basidia on grass species; aecia and spermatia on buckthorn

Habitat: prairies, woods, meadows

Fruiting Season: aecia and spermatia in spring and early summer, uredia and telia in summer and fall, basidia in spring