''Polygonum heterosepalum'', common name dwarf desert knotweed or oddsepal knotweed, is a plant species native to the

Great Basin Desert The Great Basin Desert is part of the Great Basin between the Sierra Nevada and the Wasatch Range. The desert is a geographical region that largely overlaps the Great Basin shrub steppe defined by the World Wildlife Fund, and the Central Basin a ...

in southwestern

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

, northern

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, northeastern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, and southwestern

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

. It has been reported from 1 county in California (

Modoc Modoc may refer to: Ethnic groups *Modoc people, a Native American/First Nations people ** Modoc language **Modoc Tribe of Oklahoma, a federally recognized tribe of Modoc *Modoc War, the last armed resistance of the Modoc people in 1873 *The "Mo ...

), 4 in Nevada ( Washoe, Humboldt, Elko and Lander), 4 in Idaho ( Owyhee, Twin Falls, Elmore and Gooding), and 5 in Oregon (

Lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

, Malheur, Harney,

Grant Grant or Grants may refer to: Places *Grant County (disambiguation) Australia * Grant, Queensland, a locality in the Barcaldine Region, Queensland, Australia United Kingdom *Castle Grant United States * Grant, Alabama *Grant, Inyo County, C ...

and

Crook Crook is another name for criminal. Crook or Crooks may also refer to: Places * Crook, County Durham, England, a town * Crook, Cumbria, England, village and civil parish * Crook Hill, Derbyshire, England * Crook, Colorado, United States, a ...

). The species occurs in dry, open sites in sagebrush plains and pine woodlands. ''Polygonum heterosepalum'' is a short herb up to tall, forming mats that seem rather moss-like. Stems are green or red. Leaves are densely packed, narrow up to long. Flowers are white, sometimes pink along margins, borne in groups of 2–3 in the

axils A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

of the leaves, slightly

zygomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

with some

tepals A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

longer than the others.Flora of North America, M. Peck & Ownbey, 1950. Dwarf desert knotweed
/ref>Peck, Morton Eaton & Ownbey, Francis Marion. 1950. Madroño 10(8): 250–251.

References

{{Taxonbar, from=Q16988322 heterosepalum Flora of the Western United States Plants described in 1950 Flora without expected TNC conservation status