Few-flowered Butterweed - Senecio pauciflorus
Few-flowered Butterweed is a glabrous, perennial herb with stems that are 15-40 cm high and arising from a simple or branched rootcrown with fibrous roots. The basal leaves are 3-10 cm long and have long petioles and thick, spade-shaped blades with coarsely toothed margins. The alternate stem leaves, some with a pair of basal lobes, become smaller and sessile upward. Usually, 2-6 erect flower heads are borne in a crowded, terminal inflorescence. Each flower head has a single series of reddish-purple, narrow, pointed involucral bracts that are 6-8 mm long. Disk flowers are orange to reddish. Rays are inconspicuous or lacking. The achene has a pappus at its summit.
Flowering in June.
Senecio is a large genus, and a technical manual should be consulted for positive identification. Senecio debilis and S. indecorus have more deeply lobed lower leaves and are generally found at lower elevations.
AK and YK east to QC and NL, south to CA and WY (Packer, 2000, in Fl. Alberta).
Moist meadows and cliffs in the montane zone.
The following animal species have been reported as pollinators of this plant species or its genus 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. 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.
- 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.
- 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.
- Simanonok, M. 2018. Plant-pollinator network assembly after wildfire. Ph.D. Dissertation. Bozeman, MT: Montana State University. 123 p.
- Simanonok, M.P. and L.A. Burkle. 2019. Nesting success of wood-cavity-nesting bees declines with increasing time since wildfire. Ecology and Evolution 9:12436-12445.