Polygonum aviculare rurivagum

Description

Common knotgrass is an annual herb with a semi-erect stem that may grow from 10 to 40�cm (4 to 16�in) high. The�leaves�are hairless and short-stalked. They are�longish-elliptical�with short stalks and rounded bases; the upper ones are few and are linear and stalkless. The�stipules�are fused into a stem-enclosing, translucent sheath known as an�ochrea�that is membranous and silvery. The�flowers�are regular, green with white or pink margins. Each has five�perianth�segments, overlapping at the base, five to eight stamens and three fused carpels. The fruit is a dark brown, three-edged nut. The seeds need light to germinate which is why this plant appears in disturbed soil in locations where its seeds may have lain�dormant�for years