Cronartium

Cronartium
Cronartium ribicola on Western White Pine
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Urediniomycetes
Order:	Uredinales
Family:	Cronartiaceae
Genus:	Cronartium Fr.
Species
See text.

See text.

Cronartium is a genus of rust fungi in the family Cronartiaceae.

They are heteroecious rusts with two alternating hosts, typically a pine and a flowering plant, and up to five spore stages. Many of the species are plant diseases of major economic importance, causing significant damage.

Some of the species have been introduced accidentally outside of their natural ranges, notably C. ribicola into North America, where it is an invasive species causing heavy mortality in several pines which have little or no resistance to it.

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Wikipedia