Burke: Polygonum majus vs. Polygonum utahense

	Polygonum majus	Polygonum utahense
	Palouse knotweed, wiry knotweed
Habit	Erect annual, the stem strongly angled, simple or freely-branched, 1-3 dm. tall.
Leaves	Leaves alternate, numerous, gradually reduced upward, the lower leaves linear to oblong, sessile, 2-5 cm. long and 2-7 mm. wide, jointed at the base; stipules 10-15 mm. long, lacerate.
Flowers	Flowers mostly paired in open elongate racemes, in the axils of reduced bracts or the lowest in leaf axils, the pedicles slender, reflexed; the 5 perianth segments 4-5 mm. long, attached 1/5 their length, with a greenish midvein and white to pink margins, obtuse; stamens 8, anthers purple; styles 3, short.

	Polygonum majus	Polygonum utahense
Identification notes	Achene 3-angled, 3.5-4 mm. long and Â½ as wide, smooth, black and shining, tapered at each end.
Flowering time	May-August
Habitat	Dry, often semi-barren, gravelly to heavy soil, sagebrush desert to lower mountains.
Distribution	Occurring east of the Cascades crest in Washington; British Columbia south to California, east to the Rocky Mountains. [WildflowerSearch map] [BONAP county map]	[BONAP county map]
Origin	Native
Conservation status	Not of concern
Sibling taxa	P. achoreum, P. austiniae, P. aviculare, P. californicum, P. douglasii, P. erectum, P. fowleri, P. minimum, P. nuttallii, P. paronychia, P. parryi, P. polygaloides, P. ramosissimum, P. sawatchense, P. spergulariiforme	P. achoreum, P. austiniae, P. aviculare, P. californicum, P. douglasii, P. erectum, P. fowleri, P. majus, P. minimum, P. nuttallii, P. paronychia, P. parryi, P. polygaloides, P. ramosissimum, P. sawatchense, P. spergulariiforme
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Polygonum majus

Polygonum utahense

Palouse knotweed, wiry knotweed

Habit

Erect annual, the stem strongly angled, simple or freely-branched, 1-3 dm. tall.

Leaves

Leaves alternate, numerous, gradually reduced upward, the lower leaves linear to oblong, sessile, 2-5 cm. long and 2-7 mm. wide, jointed at the base;

stipules 10-15 mm. long, lacerate.

Flowers

Flowers mostly paired in open elongate racemes, in the axils of reduced bracts or the lowest in leaf axils, the pedicles slender, reflexed; the 5 perianth segments 4-5 mm. long, attached 1/5 their length, with a greenish midvein and white to pink margins, obtuse;

stamens 8, anthers purple;

styles 3, short.