Culver's-root was listed as Threatened by regulation under Manitoba's Endangered Species Act in 2001. It is a herbaceous perennial that can grow up to 2 m (6.5 feet) tall. Leaves are lance-shaped and sharply toothed, growing up to 7 cm (2.8 inches) in length and in whorls of 3 to 7 every 13 to 18 cm (5 to 7 inches) along the stem. Its white or pinkish flowers are crowded on 5 to 15 cm (2 to 6 inch) long terminal spikes that open from the bottom up, often resembling a candelabra. Each flower is 7 to 9 mm (0.28 to 0.35 inches) long with two protruding purple anthers.
In Manitoba Culver's-root grows in tall grass prairie habitats, at the edges of thickets and open aspen/bur oak woods, adjacent to shrubs along roadsides, railway right-of-ways and fences. It prefers moist, calcareous sandy loam soil but can grow on drier upland sites. It ranges from near Kleefeld, south through Tolstoi and the surrounding area to the Manitoba-Minnesota border. Known locations include the Manitoba Tall Grass Prairie Preserve.
Threats to Culver's-root growing along roadsides include future road works, grading, mowing, herbicide spraying and picking. Land-use changes, such as the removal of hedgerows and shelterbelts, lead to habitat reduction, loss or fragmentation. Haying may damage stems in early summer or remove flowers before seed set in late summer. Grazing by deer and cattle may remove flowering stems. Other threats include drainage alterations and effects of pesticides on pollinators.
For more information on the Culver's-root view the Manitoba's
Species at Risk brochure (PDF document, 294 KB).