Isely's Milkvetch
Astragalus iselyi
NatureServe conservation status
Global (G-rank): G1
State (S-rank): S1
Utah Wildlife Action Plan status
- SGCN
External links
General information
Astragalus iselyi is currently known only from Grand and San Juan Counties of Utah. This species grows on the seleniferous and uranium rich soils of classic pinyon-juniper or desert shrub communities. Isley's milkvetch has bright white upright flowers and red stems with many ascending green leaflets, the whole plant seems to reach for the sun.
Description
Astragalus iselyi is currently known only from Grand and San Juan Counties of Utah. This species grows on the seleniferous and uranium rich soils of classic pinyon-juniper or desert shrub communities. Isley's milkvetch has bright white upright flowers and red stems with many ascending green leaflets, the whole plant seems to reach for the sun.
Phenology
Flowers from April-June.
Diagnostic characteristics
Astragalus isleyi resembles species in the Astragalus sabulosus complex in form, pubescence, and foliage, and differs only in its flower size and color. Astragalus iselyi produces immaculate white flowers measuring 17-19 mm long. A. sabulosus produces cream-colored flowers measuring 27-34 mm long, while A. vehiculus produces pink-tinged to whitish flowers measuring 23-27 mm long. A. isleyi and A. sabulosus varieties are similar in form have distinct red stems and produce downward hanging mature fruits.
Species range
A Navajo Basin endemic, found in Grand and San Juan Counties, Utah.
Threats or limiting factors
This plant seems to rely on a seed bank to survive and seen in no adults but seedilings observed in 2019 and witnessed by Fitts, 2019. Area subject to heavy grazing, some mining and recreation use, and ORV activities (USFWS 2009 citing Franklin 2003). The ongoing renewal of mining claims in the uranium rich habitat on which this plant grows is a concern (USFWS 2009).
Taxonomy
No, this species does not have taxonomic discrepancies