Forum Flora Germanica

The uredinia and telia of Coleosporium species morphologically are indistinguishable. For pictures see for instance C. melampyri and C. tussilaginis.

Coleosporium campanulae, Rust fungus
On the underside of conspicuous, yellow leaf spots, approximately 1–2 mm in size and mostly angular, there are orange to yellow, flat, cushion-shaped uredinia, which are initially covered by a blister-like layer of epidermis and often arranged in a ring.
Telia are usually found on the underside of the leaves as firm, crusty, bright red-orange, and shiny clusters that are permanently covered by the epidermis.
In the spring, spermogonia and aecia form on the needles of pine trees.