Laguna de Santa Rosa
Rose Rust is a disease caused by the parasitic fungus (Phragmidium tuberculatum) and some other closely related species. It is specific to roses, and appears in spring and persists until the leaves fall. Here it is coating an immature California Wild Rose hip with its bright orange spores. At the end of the summer the spores turn black. The spores can overwinter on the dead leaves on the ground.