Great Basin Naturalist


Comandra umbellate is the alternate host of a hard pine canker rust disease induced by the fungus Cronartium comandrae. The occurrence and density of C. umbellata were recorded near lodgepole pine stands in the Wind River District, Shoshone National Forest, Wyoming. Comandra populations occurred most often on slopes with southern aspects, particularly southwestern, and on steep slopes; these sites tended to be dry and relatively open. Comandra was also found growing under heavy perennial shrub canopy covers. It was most often associated with sagebrush but was common near other perennial shrubs as well. Overall, C. umbellata appeared to be a poor competitor with dense grass populations. Comandra was found primarily on Abies lasiocarpa/Juniperus communis, Pinusflexilis/ Hesperochloa kingii, and Artemisia tridentata/Festuca idahoensis habitats. No comandra was found in the Abies lasiocarpa/Vaccinium scoporium habitat.