Burke: Polygonum paronychia vs. Polygonum tenue

	Polygonum paronychia	Polygonum tenue
	beach knotweed, black knotweed
Habit	Low, spreading shrub-like perennial here in Washington - typically less than 30 cm., though can get up to 100 cm. tall in some parts of its range.
Leaves	Alternate, simple, narrow, 1-2 cm long, with prominent midrib.
Flowers	Small pinkish or whitish, 5-6 mm long, with 5 parts; in small clusters along stem.
Fruits	Shiny black achenes 4-5 mm long.

	Polygonum paronychia	Polygonum tenue
Identification notes	Can be separated from other Polygonum species by its perennial decumbent stems, lacerate hyaline stipules, axillary flower clusters, and coastal habitat.
Flowering time	April-September
Habitat	Coastal shorelines and sand dunes.
Distribution	Occurring west of the Cascades crest along the coast; Vancouver Island, B.C., south to Monterey, California. [WildflowerSearch map] [BONAP county map]	[WildflowerSearch 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. majus, P. minimum, P. nuttallii, 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, Turner Photog. 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 paronychia

Polygonum tenue

beach knotweed, black knotweed

Habit

Low, spreading shrub-like perennial here in Washington - typically less than 30 cm., though can get up to 100 cm. tall in some parts of its range.

Leaves

Alternate, simple, narrow, 1-2 cm long, with prominent midrib.

Flowers

Small pinkish or whitish, 5-6 mm long, with 5 parts; in small clusters along stem.

Fruits

Shiny black achenes 4-5 mm long.

Polygonum paronychia

Polygonum tenue

Identification notes

Can be separated from other Polygonum species by its perennial decumbent stems, lacerate hyaline stipules, axillary flower clusters, and coastal habitat.

Flowering time

April-September

Habitat

Coastal shorelines and sand dunes.

Distribution