Least Bladdery Milkvetch - Astragalus microcystis
Perennial from an intricately branched caudex. Herbage strigose to villous. Stems prostrate, ascending at the tip, 10–50 cm. Leaves with 9 to 15 linear-elliptic leaflets, 5–15 mm long with rounded to acute tips; stipules 3–5 mm long, basally connate, turning black with drying. Inflorescence open with 5 to 10 spreading flowers. Flowers pink to purple, often with white wings; calyx white- or black-strigillose; sepals 1–2 mm long; banner 6–9 mm long, reflexed; keel 4–5 mm long. Legume pendent, obovoid, inflated, papery, white-strigillose, 5–10 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
WY, ID and MT (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Sandy or gravelly soil of grasslands, fellfields or on streambanks; valleys to alpine (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans
, Bombus appositus
, Bombus auricomus
, Bombus bifarius
, Bombus borealis
, Bombus centralis
, Bombus fervidus
, Bombus flavifrons
, Bombus huntii
, Bombus mixtus
, Bombus nevadensis
, Bombus rufocinctus
, Bombus ternarius
, Bombus terricola
, Bombus occidentalis
, Bombus pensylvanicus
, Bombus griseocollis
, and Bombus insularis
(Macior 1974, Thorp et al. 1983, Mayer et al. 2000, Colla and Dumesh 2010, Wilson et al. 2010, Koch et al. 2012, Miller-Struttmann and Galen 2014, Williams et al. 2014).
- Literature Cited AboveLegend: View Online Publication
- Colla, S.R. and S. Dumesh. 2010. The bumble bees of southern Ontario: notes on natural history and distribution. Journal of the Entomological Society of Ontario 141:39-68.
- Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Macior, L.M. 1974. Pollination ecology of the Front Range of the Colorado Rocky Mountains. Melanderia 15: 1-59.
- Mayer, D.F., E.R. Miliczky, B.F. Finnigan, and C.A. Johnson. 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97: 25-31.
- Miller-Struttmann, N.E. and C. Galen. 2014. High-altitude multi-taskers: bumble bee food plant use broadens along an altitudinal productivity gradient. Oecologia 176:1033-1045.
- Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
- Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p.
- Wilson, J.S., L.E. Wilson, L.D. Loftis, and T. Griswold. 2010. The montane bee fauna of north central Washington, USA, with floral associations. Western North American Naturalist 70(2): 198-207.