Hey Buggy Joe!! - What is that? - Hawthorn Rust

Each of these rust fungi must alternate between a member of the plant genus Juniperus and members of the rose family (Rosaceae) in order to complete their life cycles.  The requirement to rotate between two types of widely divergent host plants coupled with the rusty color of their spores earns these fungi the collective moniker of "heteroecious" rusts.

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