The genus Astragalus (Fabaceae) in Oregon

A total of 74 taxa of the genus Astragalus are known from the state of Oregon, primarily from east of the Cascades. Twelve of the Oregon taxa are endemic to the state. Many Astragalus have a narrow geographic range and are restricted to a particular habitat. Considering this aspect of their biology, it is not surprising that at least 27 Astragalus taxa are of conservation concern in Oregon, including eight of the endemics. Ecological findings which help explain the distribution of Astragalus are discussed, and selected aspects of the morphological diversity of the genus in Oregon are described.