Western Mountain Aster -
Aster spathulatus, Aster occidentalis
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Rhizomatous perennial. Stems erect to ascending, 15–60 cm. Herbage glabrate. Leaves basal and cauline, petiolate below; blades linear to lanceolate, 3–12 cm long, entire; the upper sessile and narrower. Inflorescence open-paniculate with few heads; peduncles glabrate to densely strigose. Involucre campanulate, 6–9 mm high; phyllaries linear-oblanceolate, imbricate, green with white bases, glabrous to ciliate. Rays 15 to 40, blue or violet; ligules 7–15 mm long. Disk flowers 30 to 80, yellow becoming purple; corollas 4–8 mm long. Achenes cylindric, 2–4 mm long, hairy (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Our plants are variety
BC, AB south to CA, UT and NM (
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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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap:
(Plath 1934, Heinrich 1976, Thorp et al. 1983, Colla and Dumesh 2010, Colla et al. 2011, Koch et al. 2012, Williams et al. 2014, Tripoldi and Szalanski 2015).
Literature Cited Above
Legend: View Online Publication Colla, S., L. Richardson, and P. Williams. 2011. Bumble bees of the eastern United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 103 p. 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. Plath, O.E. 1934. Bumblebees and their ways. New York, NY: Macmillan Company. 201 p. 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. Tripoldi, A.D. and A.L. Szalanski. 2015. The bumble bees (Hymenoptera: Apidae: Bombus) of Arkansas, fifty years later. Journal of Melittology 50: doi: http://dx.doi.org/10.17161/jom.v0i50.4834 Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p. Additional References
Legend: View Online Publication Do you know of a citation we're missing? Ament, R.J. 1995. Pioneer Plant Communities Five Years After the 1988 Yellowstone Fires. M.Sc. Thesis. Bozeman, MT: Montana State University. 216 p. Culver, D.R. 1994. Floristic analysis of the Centennial Region, Montana. M.Sc. Thesis. Montana State University, Bozeman. 199 pp. Dale, D. 1973. Effects of trail use under forests in the Madison Range, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 96 pp. Fultz, J.E. 2005. Effects of shelterwood management on flower-visiting insects and their floral resources. M.Sc. Thesis. Bozeman, MT: Montana State University. 163 p. Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p. Seipel, T.F. 2006. Plant species diversity in the sagebrush steppe of Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 87 p. Zapatka, T.P. 1963. Some results of two limited hunting seasons on hen Pheasants in north central Montana. M.Sc. Thesis. Bozeman, Montana: Montana State University. 26 p.