blister rust
n 1: 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:
{white-pine rust}, {white pine blister rust}]
2: fungus causing white pine blister rust and having a complex
life cycle requiring a plant of genus Ribes as alternate
host [syn: {Cronartium ribicola}]