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Spotted Joepye-weed - Eupatorium maculatum
Other Names:
Eupatoriadelphus maculatus, Eutrochium maculatum
State Rank Reason (see State Rank above)
Eupatorium maculatum is rare in Montana where it is known from less than 20 occurrences in Carbon and Big Horn Counties. Occurrences have not been visited for at least 20 years, which means the population trend is unknown. Threats have not been reported though climate change poses a potential risk to the state's population. Due to the species overall rarity in the state, combined with a lack of current information, Eupatorium maculatum remains likely-imperiled in Montana.
Surveys that bring forth current information on distributions, population counts and viability, habitat conditions, and threats are greatly needed. Additional surveys on lands modelled as predicted suitable habitat are also needed to better inform on the species' distribution and status in Montana.
General Description
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 (A.Gray) Breitung.
Phenology
Flowering in August.
Species Range
Montana Range
Range Descriptions
Native
Range Comments
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: 34
(Click on the following maps and charts to see full sized version)
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Habitat
Moist meadows, springs, margins of spring-fed streams, and swamp thickets in the valleys and on the plains.
National Vegetation Classification System Groups Associated with this Species
Wetland and Riparian
Alkaline - Saline Wetlands
Riparian and Wetland Forest
Riparian Shrubland
Wet Meadow and Marsh
Ecology
POLLINATORS 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).
Stewardship Responsibility
Threats or Limiting Factors
Reported threats to Spotted Joepye-weed have not been reported though climate change poses a potential risk to state's populations. The MTNHP conducted a species-level assessment using the Climate Change Vulnerability Index (CCVI) in 2021, which resulted in a Moderate Vulnerable rating to climate change. Climate change including increased ambient temperatures, decreased snowpacks, and increased frequencies and severities of drought could have negative impacts on this species; however, field-based data on the timing and magnitude from climate change is not available.
References
- 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.
- MTNHP Threat Assessment. 2021. State Threat Score Assignment and Assessment of Reported Threats from 2006 to 2021 for State-listed Vascular Plants. Botany Program, Montana Natural Heritage Program, Helena, Montana.
- 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.
- Web Search Engines for Articles on "Spotted Joepye-weed"
