Species: Polygonum douglasii ssp. austiniae
Encyclopedia of Puget Sound
Austin's Knotweed is a sparsely hairy annual with erect stems that are 3-10 cm high and branched near their bases. The alternate, narrowly egg-shaped to elliptic leaves are 5-15 mm long and 1/2-1/3 as wide. The lower leaves have short petioles, while the upper leaves are sessile and smaller. There are small membranous sheaths, or stipules, surrounding the stem at the point of leaf attachment. Groups of 1-4 tiny, nodding flowers occur in the axils of all but the lowest leaves. Each flower has 5-8 stamens and 5 petal-like tepals that are 2-3 mm long and green with white or pink margins. The shiny black achenes are 3-sided and mostly 2-2.5 mm long.
Classification
Dicotyledoneae
Polygonales
Polygonaceae
Polygonum
NatureServe
Classification
Ecology and Life History
Austin's Knotweed is a sparsely hairy annual with erect stems that are 3-10 cm high and branched near their bases. The alternate, narrowly egg-shaped to elliptic leaves are 5-15 mm long and 1/2-1/3 as wide. The lower leaves have short petioles, while the upper leaves are sessile and smaller. There are small membranous sheaths, or stipules, surrounding the stem at the point of leaf attachment. Groups of 1-4 tiny, nodding flowers occur in the axils of all but the lowest leaves. Each flower has 5-8 stamens and 5 petal-like tepals that are 2-3 mm long and green with white or pink margins. The shiny black achenes are 3-sided and mostly 2-2.5 mm long.