Astragalus amphioxys var. vespertinus

(E. Sheldon) M. E. Jones

Rev. N.-Amer. Astragalus, 215. 1923.

Common names: Evening milkvetch
Endemic
Basionym: Astragalus vespertinus E. Sheldon Minnesota Bot. Stud. 1: 150. 1894
Treatment appears in FNA Volume 11.

Flowers: calyx cylindric, tube 8.8–13.2 mm, lobes 1.3–3 mm; corolla banner 23–27(–28) mm; keel 19–23.6 mm. Legumes 30–35 mm, gently incurved. Seeds 50–70.


Phenology: Flowering Apr–Jun.
Habitat: Sandy valley floors, ledges under cliffs, gravelly hillsides, in sagebrush or mountain brush communities, pinyon-juniper forests, usually on sandstone.
Elevation: 600–1800(–2000) m.

Distribution

Ariz., Colo., N.Mex., Utah.

Discussion

Variety vespertinus is found locally within the Colorado Basin and occurs from northwestern New Mexico to southwestern Colorado, through south­eastern Utah, extending to the Grand Canyon and Kanab Plateau of northwestern Arizona. It is a large-flowered, more or less northern form of the species that is, otherwise, poorly characterized.

Selected References

None.

Lower Taxa

None.
Stanley L. Welsh +
(E. Sheldon) M. E. Jones +
Astragalus vespertinus +
Evening milkvetch +
Ariz. +, Colo. +, N.Mex. +  and Utah. +
600–1800(–2000) m. +
Sandy valley floors, ledges under cliffs, gravelly hillsides, in sagebrush or mountain brush communities, pinyon-juniper forests, usually on sandstone. +
Flowering Apr–Jun. +
Rev. N.-Amer. Astragalus, +
Papilionoideae de +
Astragalus amphioxys var. vespertinus +
Astragalus amphioxys +
variety +