Spotted Joepye-weed - Eupatorium maculatum
Eupatoriadelphus maculatus, Eutrochium maculatum
State Rank Reason (see State Rank above)
Widespread species known in Montana from a few occurrences in the south-central part of the state on a variety of ownerships. Four of the occurrences are moderate to large-sized populations.
Fibrous-rooted perennial. Stems erect, 50–150 cm, simple, purplish. Herbage puberulent, glandular above. Leaves cauline, short-petiolate, simple, in whorls of 3 or 4; blades lanceolate, 6–15 cm long, serrate. Inflorescence corymbiform, flat-topped, terminal or in upper leaf axils. Heads discoid; involucre tubular, 6–9 mm high; phyllaries imbricate in 3 to 5 series, white to purplish, ovate to oblanceolate, glabrous; receptacle convex, naked. Disk flowers perfect, tubular, 9 to 22, purple; corolla 4–6 mm long; style branches clavate. Achenes obconic, 5-angled, 3–5 mm long, glandular; pappus 1 series of capillary bristles (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Our plants are variety bruneri
Flowering in August.
BC to QC south to AZ. NM, TN and NC (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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(Observations spanning multiple months or years are excluded from time charts)
Moist meadows, springs, margins of spring-fed streams, and swamp thickets in the valleys and on the plains.
Ecological Systems Associated with this Species
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans
, Bombus bifarius
, Bombus borealis
, Bombus rufocinctus
, Bombus ternarius
, Bombus pensylvanicus
, Bombus griseocollis
, Bombus impatiens
, Bombus insularis
, and Bombus bohemicus
(Plath 1934, Thorp et al. 1983, Colla and Dumesh 2010, Colla et al. 2011, Koch et al. 2012, Williams et al. 2014).
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
- Literature Cited AboveLegend: 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.
- Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ: Princeton University Press. 208 p.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- 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.