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Prairie Ragwort - Senecio plattensis
Other Names:  Packera plattensis

Native Species

Global Rank: G5
State Rank: S3S4
(see State Rank Reason below)
C-value: 4

Agency Status


External Links

State Rank Reason (see State Rank above)
Senecio plattensis has been found in the south-central and eastern portions of Montana. Observations from western Montana need to be re-examined for accuracy because taxonomy evolves, plants are variable, and some Senecio (Packera) species are difficult to distinguish. Plants appear to be common and occur in habitats that are widespread and relatively secure. Population-level data and mapping based on accurately determined specimens are always needed.
  • Details on Status Ranking and Review
    Prairie Ragwort (Senecio plattensis) Conservation Status Review
    Review Date = 08/25/2020
    View State Conservation Rank Criteria
    Range Extent

    ScoreF - 20,000-200,000 sq km (~8,000-80,000 sq mi)

    Comment52,477 square kilometers for 39 observations which represent accurately identified or likely accurately identified specimens.

    Area of Occupancy

    ScoreE - 26-125 4-km2 grid cells

    CommentMontana can be divided into 30,390 4x4 square kilometer cells. For this species plant observations occur in 34 of these 4x4 square kilometer cells.

    Number of Populations

    ScoreC - 21 - 80

    Comment39 observations.

    Environmental Specificity

    ScoreC - Moderate. Generalist or community with some key requirements scarce


    ScoreD - Low

General Description
PLANTS: Perennial plants that grow erect stems, 10-40 cm tall and fibrous roots from a rhizome or short caudex. Plants have tangled, cobweb-like hairs (arachnoid-tomentose), but sometimes sparsely on leaves. Source: Lesica et al. 2012

LEAVES: Basal and arranged alternately on the stem. Basal leaves are long-petiolate with ovate to lanceolate blades that are crenate to lobed, and 2–5 cm long. Stem (cauline) leaves becoming sessile upwards with narrower, pinnate lobes. Source: Lesica et al. 2012

INFLORESCENCE: Yellow flowers occur in heads that are arranged in corymbs. Heads have male and female organs (radiate) and are 4-20 in number. Involucres are campanulate, 5–9 mm high. Involucral bracts are 13 or 21, tomentose. Ray florets are 8 to 10 in number with petals (ligules) 5–10 mm long. Disk florets are 5–7 mm long. Fruit is an achene. Source: Lesica et al. 2012

Diagnostic Characteristics
Prairie Ragwort - Senecio plattensis
*Hairs: At flowering, leaves and stems are arachnoid to tomentose. The arachnoid hairs can be sparse to dense.
*Stem Leaves: Blades are ovate to lanceolate, and divided into narrow, crenate lobes.
*Habitat: Grasslands and pine woodlands.

Balsam Ragwort - Senecio pauperculus
*Hairs: At flowering, leaves and stems are glabrate, but can be sparse tomentum (not arachnoid) in the leaf axils.
*Stem Leaves: Blades are lanceolate to oblanceolate, and divided into narrow, deeply-lobed.
*Habitat: Wetlands, moist meadows, or wet meadows.

Species Range
Montana Range Range Descriptions


Range Comments
Saskatchewan to Quebec in Canada south to New Mexico, Kansas, Louisiana, and Alabama U.S. (Lesica et al. 2012).

Observations in Montana Natural Heritage Program Database
Number of Observations: 44

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Mesic grasslands and pine woodlands in the plains zone of Montana (Lesica et al. 2012).

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.
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 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
    Do you know of a citation we're missing?
    • DuBois, K.L. 1979. An inventory of the avifauna in the Long Pines of Southeastern Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 113 p.
    • Fritzen, D.E. 1995. Ecology and behavior of Mule Deer on the Rosebud Coal Mine, Montana. Ph.D. Dissertation. Bozeman, MT: Montana State University. 143 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.
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Citation for data on this website:
Prairie Ragwort — Senecio plattensis.  Montana Field Guide.  .  Retrieved on , from