Fireweed, Chamerion angustifolium, is a robust strongly-spreading, rhizomatous perennial wildflower that grows to 2-5 feet tall on upright, often reddish, primarily unbranched, stiff woody stems clad with alternate, narrow-lanceolate or linear, pinnately-veined, willow-like leaves (to 2-6 inches long and ¾-inch wide) and topped by an elongated terminal cluster (raceme to 3-8 inches long) of open, saucer-shaped, 4-petaled, bright pink to lilac-purple (rarely white) outward-facing flowers with protruding stigmas which bloom in summer (June-September). Flowers bloom bottom to top on each raceme which can simultaneously have seed pods at the bottom, blooming flowers in the middle and unopened flower buds at the top.
The blooming period occurs primarily from early to late summer, and lasts about a month. The flowers quickly wither away, and are replaced by seed pods that are long and narrow. These seed pods split into multiple sections, beginning at their tips (each section curling backward), and release a multitude of tiny seeds with small tufts of white hair. These seeds are readily dispersed by the wind, and can travel a considerable distance. The root system is fibrous and rhizomatous, which enables this plant to form colonies.
It is found in a variety of locations including open woods, roadsides, open fields, pastures, prairies, hills, damp ravines, logged and burned areas, and especially along streams, in damp places and on disturbed sites from low valleys to tree line in the mountains
Easily grown in organically rich, well-drained soil in full sun to part shade. Prefers part shade in hot summer climates. Needs regular moisture. Promptly remove spent flower stems to encourage additional bloom and to prevent unwanted self-seeding. Plants spread by both rhizomes and self-seeding (seeds have silky seed hairs which facilitate easy dispersal by the wind to remote areas). This plant can be both persistent and aggressive in g