Glenwood Milkvetch
Astragalus loanus
NatureServe conservation status
Global (G-rank): G1
State (S-rank): S1
Utah Wildlife Action Plan status
- SGCN
External links
General information
Astragalus loanus is known only from Sevier County, Utah where it is found growing in Sevier valley. This species is often associated with sagebrush and pinyon-juniper communities and is found on gravely hillsides. Glenwood Milkvetch is a tiny wonder having showy white flowers with purple tipped keel petals that peak out and help us positively identify this rare plant in this region. This species is also a unique Astragalus species having rhombic leaflets that are widely ovate and densly hairy with malpighian hairs.
Description
Astragalus loanus is stemless perennial plant that measures 3-6 cm tall forming from a branching caudex. The leaves are 2-8 cm long with 3-5 pairs of ovate leaflets each measuring 6-25 mm long and 5-20 mm wide.
Phenology
This species flowers between May and early June.
Diagnostic characteristics
Astragalus calycosus var. calycosus is another tiny milkvetch found in the Sevier Valley, Utah and elsewhere. Astragalus loanus and Astragalus calycosus var. calycosus can be positively identified by their flowers and leaves as follows:
Astragalus loanus has flowers that are white with a purple keel tip and in racemes of just 2-7 flowers per raceme. The leaflets are ovate or rhomboid and densely hairy with hairs that do not give the plant a green appearance and not a silvery, grey appearance.
Astragalus calycosus var. calycosus has flowers that can be variously white, pink, purple, or blue but the keel tip remains maculate white in all variations otherwise and the flowers are either in short, loose, 1-8 flowered racemes or more openly with 7-17 flowers per inflorescence. The leaflets are obovate to elliptic and densely hair with silvery, grey hairs giving the plant a silvery, grey appearance.
Species range
A Southern Plateaus endemic, found in Sevier County, Utah.
Map
Threats or limiting factors
Threats include drought, invasive plant species and human disturbances (PJ removal treatments). The PJ removal treatment area produced a brief increase in its numbers, but with time has trended negatively. Cheatgrass and russian thistle have been noted as threats. Whitetop and bindweed have also been noted in the area. A die-off in 2025 was observed, presumably due to drought. Ongoing monitoring efforts will hopefully provide further information on long term trends. Although all occurrences are within grazing allotments impacts from grazing are likely low.
Taxonomy
No, this species does not have taxonomic discrepancies