Herbs, or sometimes shrubby plants, with alternate or opposite leaves, and axillary or terminal, solitary, spicate or racemose flowers. Calyx-tube linear, produced beyond the ovary, the limb 4-parted, deciduous. Petals 4, mostly obovate or obcordate. Stamens 8; anthers oblong or linear, short. Ovary 4-celled; united styles slender or filiform; stigma club-shaped or 4-lobed; ovules numerous. Capsule narrow, elongated, 4-sided, 4-celled, loculicidally dehiscent by 4 valves. Seeds small, numerous, with a tuft of hairs (coma) at the summit. [Greek, upon a pod, flower and pod appearing together.]

About 75 species. of wide geographic distribution, most abundant in temperate regions. Besides the following, about 35 others occur in the western and northwestern parts of North America. Type species: Epilobium hirsutum L.

Stigma deeply 4-lobed; flowers large.

1.

E. hirsutum.

Stigma entire, or merely notched.

Seeds smooth or nearly so; arctic or alpine species.

Flowers white; leaves usually denticulate.

2.

E. alpinum.

Flowers violet; leaves mostly entire.

3.

E. anagallidifolium.

Seeds papillose.

Leaves linear or lanceolate, entire or nearly so.

Plants crisp-pubescent or canescent.

Leaves sessile, not revolute-margined.

4.

E. palustre.

Leaves petioled, very narrow, acute, revolute-margined.

5.

E. lineare.

Plants glandular-pubescent, at least above.

Densely pubescent throughout; leaves sessile.

6.

E. strictum.

Glandular-pubescent above; leaves petioled.

7.

E. paniculatum.

Leaves lanceolate or ovate, serrate.

Leaves lanceolate, acute or acuminate; stems solitary.

Seeds obconic, beakless; coma reddish; leaves narrowly lanceolate.

8.

E. coloratum.

Seeds ellipsoid, short-beaked; coma white; leaves oblong-lanceolate to ovate-lanceolate.

9.

E. adenocaulon.

Leaves ovate, thin, obtuse, or the upper acutish; stems tufted.

10.

E. Hornemanni.