Bistorta vivipara (L.) S.F. Gray
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Persicaria vivipara, Polygonum viviparum
Basis for Listing
Bistorta vivipara (alpine bistort) is usually considered an arctic/alpine species, occurring primarily in high latitude, arctic habitats across North America. It also ranges southward in alpine habitats in the Rocky Mountains. Its occurrence in Minnesota is seemingly anomalous and can be explained by the localized, arctic-like conditions that exist in certain microhabitats along the north shore of Lake Superior. The species is known to occur at about a dozen locations in Minnesota, most are in a relatively small area along the shore of Lake Superior in Cook County (North Shore Highlands Subsection). Plants in this area may be part of a single metapopulation, where local extirpations are matched by recolonization. The total number of individuals is quite small, probably numbering in the hundreds, rather than the thousands. Habitats are correspondingly small, probably totaling less than 1 ha (2.5 ac.). The looming threat is non-compatible recreational activity that is accompanying the building boom along the shore. All this was known, or suspected, when B. vivipara was listed as special concern in 1984. However, it was hoped that a thorough ground search by experienced botanists would reveal both more potential habitat and more populations. A thorough ground search has now been completed, and the results are discouraging. Few previously unknown habitats were discovered, and even fewer new populations were found. For these reasons, the status of B. vivipara was changed to threatened in 2013.
The flowering stem of B. vivipara is rather short, usually no more than 15 cm (5.9 in.) tall. The single spike of flowers is 2-10 cm (0.8-3.9 in.) long, with several small white or pinkish flowers. The basal leaves have a slender petiole and a lance-oblong or lanceolate blade that narrows to a pointed tip. They are 2-10 cm (0.8-3.9 in.) long, stiff, and pale green. The stem leaves are similar, only smaller, and often without a petiole.
Bistorta vivipara occurs primarily on the wet, cobble beaches and, to a lesser extent, in bedrock crevices along the rocky shore of Lake Superior. In many cases, it is found growing in the shade of shrubs such as Alnus spp. (alders), in thick, mossy patches of soil over boulders or bedrock, generally within 30 m (100 ft.) of the water. It is thought to occur there because of the unique microclimate provided by the lake.
Biology / Life History
A curious feature of this species is implied by its specific epithet, "viviparum". It is indeed viviparous, meaning that young plants can develop on the parent plant. In other words, a single inflorescence can produce seeds from flowers, as well as vegetative propagules in the form of bulbils (young leafy plantlets) (Law et al. 1983). Beyond that, little is known about the specific biology or life history of B. vivipara in Minnesota, except that it is clearly adapted to harsh, alpine-like conditions (Given and Soper 1981). This includes a short, cool, growing season and a correspondingly long winter, where its habitat might be exposed to desiccating winds and ice scouring.
Conservation / Management
The shore rocks along Lake Superior are millions of years old and seem indestructible. In contrast, the wet, cobble beach habitat and the small vegetation mats in the rock crevices, where B. vivipara occurs, are very fragile and easily destroyed. Activities as benign as hiking can become a serious threat, if concentrated along the shore. Consequently, all foot traffic should be routed away from known occurrences of B. vivipara. The same is true for camping, campfires, and other similar activities.
Best Time to Search
The best time to search for B. vivipara is from early June through the end of July.
Welby Smith, MN DNR, 1988, 2008, and 2017
Bauert, M. R. 1996. Genetic diversity and ecotypic differentiation in arctic and alpine populations of Polygonum viviparum. Arctic and Alpine Research 28:190-195.
Coffin, B., and L. Pfannmuller, editors. 1988. Minnesota's endangered flora and fauna. University of Minnesota Press, Minneapolis. 473 pp.
Dingle, P. K., M. A. Meixner, A. B. Carroll, and C. F. Aschwanden. 2002. Barriers to sexual reproduction in Polygonum viviparum: A comparative developmental analysis of P. viviparum and P. bistortoides. Annals of Botany 89:145-156.
Freeman, C. C., and H. R. Hinds. 2005. Bistorta. Pages 594-596 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 5. Oxford University Press, New York, New York.
Given, D. R., and J. H. Soper. 1981. The arctic-alpine element of the vascular flora at Lake Superior. National Museum of Canada, Publications in Botany No. 10, Ottawa, Ontario. 70 pp.
Law, R., R. E. D. Cook, and R. J. Manlove. 1983. The ecology of flower and bulbil production in Polygonum viviparum. Nordic Journal of Botany 3:559-565.
Minnesota Department of Natural Resources. 2003. Field guide to the native plant communities of Minnesota: the Laurentian mixed forest province. Ecological Land Classification Program, Minnesota County Biological Survey, and Natural Heritage and Nongame Research Program. Minnesota Department of Natural Resources, St. Paul, Minnesota. 352 pp.
Minnesota Department of Natural Resources, Division of Ecological Resources. 2008. Rare species guide: an online encyclopedia of Minnesota's rare native plants and animals [Web Application]. Minnesota Department of Natural Resources, St. Paul, Minnesota. Accessed 1 July 2009.
Penskar, M. R. 2008. Special plant abstract for Polygonum viviparum (alpine bistort). Michigan Natural Features Inventory, Lansing, Michigan.