Large-headed Ragwort - Senecio megacephalus
MNPS Threat Rank
Fibrous-rooted from a short or branched caudex. Stems erect, 20–60 cm. Herbage arachnoid. Leaves basal and cauline; blades linear-lanceolate to oblanceolate, entire, 3–15 cm long, greatly reduced above. Inflorescence a solitary (2 to 4) head. Heads radiate; involucres 10–25 mm high; phyllaries ca. 21, arachnoid. Rays ca. 13; ligules 12–22 mm long. Disk flowers 9–14 mm long. Achenes 2–6 mm long, glabrous (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Endemic to northwest MT, adjacent ID and Canada (Lesica 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)
Stony soil of meadows, grasslands, open forest, fellfields; upper montane to alpine (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
The following animal species have been reported as pollinators of this species or genera where their geographic ranges overlap: Bombus bifarius
, Bombus flavifrons
, Bombus frigidus
, Bombus huntii
, Bombus melanopygus
, Bombus mixtus
, Bombus sylvicola
, Bombus occidentalis
, Bombus insularis
, Bombus suckleyi
, Bombus flavidus
, and Bombus kirbiellus
(Schmitt 1980, Thorp et al. 1983, Mayer et al. 2000, Wilson et al. 2010, Pyke et al. 2012, Koch et al. 2012, Williams et al. 2014).
- Literature Cited AboveLegend: View Online Publication
- Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
- 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.
- Pyke, G.H., D.W. Inouye, and J.D. Thomson. 2012. Local geographic distributions of bumble bees near Crested Butte, Colorado: competition and community structure revisited. Environmental Entomology 41(6): 1332-1349.
- Schmitt, J. 1980. Pollinator foraging behavior and gene dispersal in Senecio (Compositae). Evolution 34: 934-943.
- 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.
- 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.
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.