|Dwarf desert knotweed|
M.Peck & Ownbey 1950
Polygonum heterosepalum, common name dwarf desert knotweed or oddsepal knotweed, is a plant species native to the Great Basin Desert in southwestern Idaho, northern Nevada, northeastern California, and southwestern Oregon. It has been reported from 1 county in California (Modoc), 4 in Nevada (Washoe, Humboldt, Elko and Lander), 4 in Idaho (Owyhee, Twin Falls, Elmore and Gooding), and 5 in Oregon (Lake, Malheur, Harney, Grant and Crook). The species occurs in dry, open sites in sagebrush plains and pine woodlands.
Polygonum heterosepalum is a short herb up to 5 centimetres (2.0 in) tall, forming mats that seem rather moss-like. Stems are green or red. Leaves are densely packed, narrow up to 3 millimetres (0.12 in) long. Flowers are white, sometimes pink along margins, borne in groups of 2-3 in the axils of the leaves, slightly zygomorphic with some tepals longer than the others.
- Flora of North America, M. Peck & Ownbey, 1950. Dwarf desert knotweed
- BONAP (Biota of North America Project) 2014 county distribution map
- photo of isotype of Polygonum heterosepalum at Missouri Botanical Garden
- Hitchcock, C. H., A.J. Cronquist, F. M. Ownbey & J. W. Thompson. 1984. Salicaceae to Saxifragaceae. Part II: 1–597. In C. L. Hitchcock Vascular Plants of the Pacific Northwest. University of Washington Press, Seattle.
- Peck, Morton Eaton & Ownbey, Francis Marion. 1950. Madroño 10(8): 250–251.