A rust fungus on both sides of leaves of Gentianella amarella (autumn gentian or autumn felwort), visible as discrete 0.5 mm diameter cinnamon-brown pustules.
Uredosori amphigenous (on both sides of leaves), without spots, scattered, minute, rounded, about 0.5 mm. diam., surrounded by the ruptured epidermis, pulverulent (powdery), pale cinnamon-brown; uredospores globoid, 20-26 x 16-22 µm, wall 1-2 µm thick, echinulate (set with small spines) with 3, less commonly 2, equatorial pores. Teliosori amphigenous, resembling the uredosori, cinnamon-brown; teliospores globoid, cinnamon-brown, 15-18 x 18-21 µm, wall 1.5 µm thick, finely verrucose (covered in warts), pore with a low, hyaline papilla, pedicel (stem or stalk) hyaline, short, fragile and deciduous (falling off when mature). Possibly a hemi-form (possessing a reduced life cycle comprising only uredial and telial stages).
Description adapted from Wilson, M. & Henderson, D. M. (1966). British rust fungi.