Yellow Fireweed

Epilobium luteum

Stems erect, usually unbranched, flowers yellow. Stems bear opposite sessile leaves. Leaves 1–3 in. long, serrate, widely lance-shaped. Flowers near stem top nod in bud, then become upright; 4 petals 1/2–3/4 in. long, widely oval, with notched tip. Tube 1 1/2–3 in. long, becomes seedpod. Grows in seeps, edges of lakes, streams, springs, at mid to high elevations. Epilobium is Greek and refers to the sepals and petals located on top of the long pod, the ovary tube.
Yellow Fireweed  Epilobium luteum,Geotagged,Summer,United States,Yellow Fireweed

Appearance

General: Herbaceous perennial from widespread rhizomes, the stems simple, erect, 2-7 dm. tall; pubescent in lines down the stems.
Leaves: Leaves mostly opposite, sub-sessile, ovate-lanceolate to lanceolate, 3-8 cm. long, glandular-serrulate to glandular-dentate, glabrous.
Flowers: Flowers 2-10, axillary in the reduced upper leaves; pedicels 5-30 mm. long; calyx tube cup-shaped, 1-2 mm. long, the 4 lobes linear-lanceolate, 8-13 mm. long; petals 4, yellow, shallowly obcordate, 14-18 mm. long; stamens 8; style much longer than the petals; stigma lobes 4, oblong-ovate, 2 mm. long; ovary inferior, 4-celled.
Fruits: Capsule linear, 4-8 cm. long; seeds with a tuft of rust-colored hairs at the tip.

Distribution

In the Olympics and Cascades in Washington; Alaska south to California.

Habitat

Stream banks and wet areas at mid- to high elevations in the mountains.

References:

Some text fragments are auto parsed from Wikipedia.

http://biology.burke.washington.edu/herbarium/imagecollection.php?Genus=Epilobium&Species=luteum

http://www.pnwflowers.com/flower/epilobium-luteum
Taxonomy
KingdomPlantae
DivisionAngiosperms
ClassEudicots
OrderMyrtales
FamilyOnagraceae
GenusEpilobium
SpeciesEpilobium luteum