Polygonum pensylvanicum (purple head, pinkweed, hearts-ease, swamp persicary, glandular persicary)

description: summer annual

place of origin: eastern North America and Europe

urban habitat: can grow in dry compacted soils in full sun; common at the base of stone walls, in vacant lots and waste areas, on disturbed soil adjacent to wetlands and in drainage ditches.

ecological function: disturbance-adapted colonizer of bare ground; food and habitat for wildlife.

history: Native Americans used Polygonum pensylvanicum to make a tea to treat a variety of ailments including diarrhea, hemorrhoids, heart ailments, stomachaches, kidney stones, epilepsy, and as foot soak for leg and foot pain. A poultice from the whole plant continues to be used as treatment for poison ivy rash and as insect repellent.