Impatiens glandulifera

Himalyan balsam looks like a very tall jewelweed, only with pink (& occasionally white) flowers. It is quite attractive but spreads very rapidly in moist soils, taking light, space, and even pollinators from native species. An annual, it leads to erosion on stream banks where it becomes a monoculture that replaces deeper rooted perennials. One plant can produce several hundred seeds in a season. Please do not plant.