Pennsylvania Smartweed

Pennsylvania Smartweed
Pennsylvania Smartweed. Polygonum pennsylvanicum, also Persicaria pennsylvanica.
Polygonaceae, the buckwheat, smartweed or knotweed family.

Plant: Erect, sometimes branching plant 1'-4', with upright, dense cylindrical clusters of small pink flowers. Flower stalks are sticky-hairy. Perennial
Flowers: Tiny, pink, about 1/8" across, in erect, dense, cylindrical spikes 1/2"-2" long. Four to six (often five) petal-like sepals; petals are absent.
Leaves: Alternate, narrowly ovate to lanceolate, 4"-6", petioles short, margins smooth. Characteristic sheath where leaf emerges is hairless
Fruit: Two-sided seeds
Blooming: June-October
Habitat: Moist waste areas, gardens and fields.

Comments: This native smartweed is distinguished from the similar Pale or Dock-leafed Smartweed (P. lapathifolium) by having erect rather than arching flower clusters. This and other smartweeds have recently been placed in the genus Persicaria by some authorities.

Where to find it: I have seen this plant at the Jefferson Road end of the slough that runs along the entrance road, also in a wet, weedy area by the west trail. The plants do not seem to be particularly long-lived, so location may not be reliable.