Two-leaf Ragwort - Senecio dimorphophyllus
Fibrous-rooted from a short rhizome or branched caudex. Stems erect, 10–30 cm. Herbage glabrous. Leaves thick, long-petiolate below; basal blades obovate to suborbicular, sometimes cordate, crenate, 1–4 cm long; cauline lanceolate to oblanceolate, pinnately lobed or toothed, the lower clasping. Inflorescence corymbiform with 1 to 12 heads. Heads radiate; involucres 5–8 mm high; phyllaries 13 or 21, glabrous, green with ciliate tips. Rays 8 or 13; ligules 3–8 mm long. Disk corollas 4–6 mm long. Achenes 2–3 mm long, glabrous (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
We have varieties dimorphophyllus
MT to NV, UT and NM (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
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 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
Do you know of a citation we're missing?
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Seipel, T.F. 2006. Plant species diversity in the sagebrush steppe of Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 87 p.
- Simanonok, M. 2018. Plant-pollinator network assembly after wildfire. Ph.D. Dissertation. Bozeman, MT: Montana State University. 123 p.