This plasmogamy forming dikaryotic mycelium. The uredia then develop into telia bearing teliospores at the end of the season. Rusts may be heteroecious or autoecious. Hypertrophy on barberry plant. Avoid heavy use of N fertilizer and dense planting.
Monoculture is a prime cause of rust outbreaks.
Spread from Asia to Europe to North America. Very serious disease new in New Mexico. Wipe out white pine very effectively. Macrocyclic rust with White pine being the aecial host and Ribes spp. Can kill pines in one or a few years depending upon the age of the tree.