Cottonwoods , close relatives of aspens, grow along rivers and creeks in the valley and lower parts of mountain canyons. Bark on mature trees is heavily furrowed. The species that occur in the park lance leaf cottonwood, narrow leaf cottonwood and balsam poplar hybridize freely, so identification of individual species may be difficult. Common Shrubs Big sagebrush thrives in dry habitats and carpets most of the valley floor. Tiny yellow flowers bloom in August.
Antelope bitterbrush occurs with sage-brush in the southern half of Jackson Hole.
Bitterbrush grows to three feet tall. Cream-colored flowers bloom in June. Huckleberry grows two to four feet tall in lodgepole pine forests in the valley and mountain canyons. Purple berries are produced in August. Serviceberry grows to ten feet tall.