Vesicular-Arbuscular Mycorrhizae Associated with Actinomycete-Nodulated Shrubs, Cercocarpus montanus Raf. and Purshia tridentata (Pursh) DC.

Roots and rhizosphere soil of representative plants of Cercocarpus montanus Raf. and Purshia tridentata (Pursh) DC. were collected from several locations in New Mexico and the Laramie and Medicine Bow Mountains of southeastern Wyoming and examined for vesicular-arbuscular (VA) mycorrhizal symbionts. Spores of VA mycorrhizal fungi were isolated from rhizosphere soil and identified. Field plants were found heavily infected with VA mycorrhizal fungi. The isolated mycorrhizal symbionts were identified as species of Glomus. Microscopic examination of roots suggested Gigaspora and Acaulospora species were also present. All species identified at the generic level have not been previously described.