The leaves of Polygonum hydropiper are lanceolate or elliptic lanceolate, 4 to 8 cm long and 0.5 to 2.5 cm wide. The top of the leaves gradually becomes sharp, the base of the leaves is wedge-shaped, the edge has the whole edge, the two sides of the leaves are hairless, with brown dots, and the petiole is 4 to 8 mm long.
The leaves of Polygonum hydropiper are broadly ovate, ovate lanceolate or broadly elliptic, 10 to 20 cm long and 5 to 12 cm wide, with the tip gradually becoming sharp, the base of the leaves is round or nearly heart-shaped, and the edge is entire.
The racemes of Polygonum hydropiper are spicate, terminal or axillary, 3-8 cm long, usually drooping, with sparse flowers and discontinuous lower parts. The bracts of the flowers are funnel-shaped, 2-3 mm long, green. The flowers are green, with 5 deep cracks, and the upper part is white or light red.
Polygonum hydropiper raceme is spicate, terminal or axillary, 3 to 7 cm long, the flowers are close, slightly drooping, and usually several more form a panicle, the flowers are reddish or white.
