Pennsylvania smartweed

Polygonum pensylvanicum

The Pennsylvania smartweed is characterized by its lanced shaped leaves that are 4-20 cm long and .5-5 cm wide and are alternating on the stem. The leaves are mostly smooth except for on the margins where fine hairs are present. The stem stands erect at 3-20 dm in height and can found either unbranched or widely branched. The stem also has small sticky glandular hairs. Around each node on the stem a membranous sheath (ocreae) is formed. The puffed-up nodes appear red in color. Pink flowers blossom in mid spring through late fall and appear in dense clusters. They also occasionally can be found with white or bright pink flowers. The Pennsylvania smartweed also produces a dark brown or black fruit in a shiny, two edged achene.