Rosebay Willowherb

Epilobium angustifolium

Description:

This native perennial plant is 2-5' tall, and is either unbranched or sparsely branched. The smooth stems are round or somewhat angular; they often become reddish in the sun near the inflorescence. The willow-like hairless leaves are up to 5" long and ¾" across. They are narrowly lanceolate or linear, with margins that are smooth or slightly serrated (widely spaced), and are sessile or with short petioles. The central stem and upper side stems each terminate in an elongated raceme of showy flowers, about 3-8" long. These flowers range in color from pink to magenta, depending on the local ecotype. Each flower is about 1" across, consisting of 4 petals and 4 sepals. The petals are narrow at the base, but become broad and rounded toward their tips. The sepals are long and narrow; they are usually a darker color than the petals. In the center of the flower, there are up to 8 long white filaments with large magenta anthers; these anthers eventually shrivel and turn brown. The pedicels of the flowers are rather long and colored magenta. The blooming period occurs primarily from early to late summer, and lasts about a month. There is no floral scent. The flowers quickly wither away, and are replaced by seedpods that are long and narrow. These seedpods 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.