Cedar-Hawthorn Rust

Rusts Arise!

Colorful displays of three types of rust fungi are appearing on junipers in Ohio. The fungi belong to the genus Gymnosporangium and they complete part of their life-cycle on members of the plant genus Juniperus and the other part of their life-cycle on members of the family Rosaceae. In biological terms, this type of life-cycle is known as "heteroecious."
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Authors
Joe Boggs

Rusty Hawthorns

This is the time of the year when rust diseases make it easy to spot wild hawthorns growing along Ohio trails as well as in landscapes. They have orange spotted leaves and "orange-hairy haws." I may be exaggerating a bit, but these rust symptoms can certainly make woodland hikes interesting.
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Authors
Joe Boggs

Junipers Garnished with Tangerine Tentacles and Orange Goo.

Our wet weather this spring has triggered spectacular spore production by three types of rust fungi on junipers in southwest Ohio.  All three fungi belong to the genus Gymnosporangium and each must alternate between a member of the plant genus Juniperus and members of the rose family (Rosaceae) in order to complete their life cycle.  The requirement to cycle 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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Published on
Authors
Joe Boggs