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Dense-flower Knotweed -
Polygonum polygaloides ssp. confertiflorum
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Ten collections exist at MONTU from five different counties. Typical habitat includes the margins of vernal pools and ponds but is also known from roadcuts and other seasonally moist habitats. Dense-flower knotweed has been found from valley bottoms to moderate elevations in the mountains. Though it has been considered rare in the state and range-wide, it appears likely that it will be found to be more common than previosuly thought.
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Hickman (1993) lists: northern California to Washington, Wyoming and Montana. Several other sources corroborate Hickman under the synonym Polygonum confertiflorum: Peck (1961) lists Willamette Valley and east of Cascades in Oregon. Kartesz (1988) cites only Elko County, Nevada. Lackschewitz (1991) notes one report from southwest Ravalli County, Montana. Davis (1952) confirms P. confertiflorum in Idaho. And Scoggan lists a range of southwest Saskatchewan south to northern California and northern Wyoming. Kartesz (unpublished data 1995) also includes Alberta, British Columbia, Arizona and New Mexico for P. polygaloides ssp. confertiflorum.
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)
Grows in vernally flooded places that are desiccated in summer. Such habitats are very rare in Montana due to the continental climate and the porous substrates in valley floors.
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap:
(Macior 1974, Colla and Dumesh 2010).
Literature Cited Above
Legend: View Online Publication 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. Macior, L.M. 1974. Pollination ecology of the Front Range of the Colorado Rocky Mountains. Melanderia 15: 1-59. Additional References
Legend: 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. Web Search Engines for Articles on "Dense-flower Knotweed"