'blister rust' definitions:

Any of several diseases of pines caused by rust fungi of the genus Cronartium and marked by destructive invasion of bark and sapwood and producing blisters externally [syn: blister rust, white-pine rust, white pine blister rust]

Fungus causing white pine blister rust and having a complex life cycle requiring a plant of genus Ribes as alternate host [syn: blister rust, Cronartium ribicola]