Category Archives: Rusts

Serviceberry Galls

Gymnosporangium clavipes is a widespread rust (fungus) that infects over 480 species in 11 genera. Also called cedar quince/hawthorn rust, G. clavipes is heteroecious, meaning that it requires two alternate hosts to complete it life cycle. One host, various members … Continue reading

Posted in Fungi, galls, Rusts, Shrubs | Tagged , , , , , | 2 Comments

Cedar Quince/Hawthorn Rust

This gallery contains 6 photos.

The cedar quince/hawthorn rust (Gymnosporangium clavipes) is heteroecious, that is, it requires two different host species to complete its life cycle. The cedar quince/hawthorn rust winters as a stem gall on a juniper or a cedar host – its primary … Continue reading

More Galleries | Tagged , , , , , , , , | 1 Comment

Western Gall Rust Fungus

This gallery contains 4 photos.

The western gall rust fungus (Endocronartium harknessii) induces globular, woody stem galls on several pine species throughout the West. The pictured galls infected a ponderosa pine (Pinus ponderosa) growing near the shore of Baum Lake (Lassen County CA). The galls … Continue reading

More Galleries | Tagged , , , , | 3 Comments

Serendipity

This gallery contains 6 photos.

On a rocky slope overlooking Ash Creek (Lassen County CA), Leonard and I found a strange plant. The top leaves were bright yellow and sticky with green leaves lower on the stem. The yellow part of the plant did not … Continue reading

More Galleries | Tagged , , , ,

Juniper Witches’ Brooms

This gallery contains 4 photos.

Witches’ brooms on plants are an abnormal cluster of twigs or shoots arising from a single point on a stem or branch and can be caused by physical injury or the invasion of an organism. Mistletoes (see “Mistletoe“, one of … Continue reading

More Galleries | Tagged , , , , | 6 Comments