Epilobium glandulosum Lehmann, Nov. Stirp. Pug. 2: 14. 1830; E. affine Bongard; E. boreale Haussknecht; E. brevistylum Barbey; E. ciliatum var. glandulosum (Lehmann) Dorn; E. cinerascens Piper; E. delicatum Trelease; E. glandulosum var. asiaticum H. Hara; E. glandulosum var. brionense Fernald; E. glandulosum var. cardiophyllum Fernald; E. glandulosum var. cinerascens (Piper) M. Peck; E. glandulosum var. kurilense (Nakai) H. Hara; E. kurilense Nakai; E. maximowiczii Haussknecht; E. sandbergii Rydberg; E. tetragonum Linnaeus var. glandulosum (Lehmann) Torrey & A. Gray

Herbs usually with large (5–12 mm), condensed, subsessile turions 1–10 cm below ground, leaving dark scales, rarely with rosettes of fleshy leaves. Stems 20–110(–170) cm, thick, simple or sparsely branched distally, subglabrous proximal to inflorescence with raised strigillose lines from margins of petioles, densely mixed strigillose and glandular puberulent distally, or rarely villous throughout. Leaves: petiole 0–4(–10) mm; blade obovate to broadly elliptic proximally, usually narrowly ovate to ovate or broadly elliptic, rarely lanceolate distally, 3–10.5(–16) × 1–4.5(–5.5) cm, apex obtuse to subacute; bracts usually not much reduced. Inflorescences erect racemes, simple or sometimes branched, congested, 5–60(–85) cm. Flowers: floral tube 1–2.6 × 1.4–3.5 mm; sepals 4.5–7.5 × 1.2–1.8 mm; petals usually rose-purple to pink, rarely white, 4.5–12(–14) × 2.5–6.3 mm; filaments white or cream to purple, those of longer stamens 3–6.5 mm, those of shorter ones 1.4–4.3 mm; style 2.4–8.2 mm, stigma 1.2–2.3 × 0.6–1 mm, sometimes exserted beyond anthers. Capsules 40–85 mm, mixed strigillose and glandular puberulent; pedicel 5–25 mm, rarely subsessile. Seeds 1.1–1.6(–1.9) × 0.4–0.6 mm, chalazal collar 0.05–0.3 × 0.2–0.4 mm. 2n = 36.

Flowering May–Sep. Damp banks of streams and lakes, seeps, wet meadows in montane, subalpine and maritime areas; 0–3400 m; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon; Alaska, Calif., Colo., Idaho, Maine, Mass., Minn., Mont., Nev., N.H., N.Mex., Oreg., Utah, Vt., Wash., Wis., Wyo.; e Asia (Russian Far East).

Subspecies glandulosum has a geographical range almost entirely within the larger range of subsp. ciliatum. Despite this overlap, the two taxa tend to grow in different habitats and are only rarely functionally sympatric, with subsp. glandulosum in cooler, more stable habitats, often at higher elevations, and subsp. ciliatum in drier, more disturbed and open habitats. Where they occur in close sympatry, they sometimes intergrade, broadening each other’s overall variability. In northern Canada and Alaska, subsp. glandulosum tends to replace subsp. ciliatum, notably along coastal Alaska, where it also replaces subsp. watsonii. In Nunavut, subsp. glandulosum is known only from Akamiski Island in James Bay.

As discussed under 30. Epilobium luteum, subsp. glandulosum hybridizes with that species—both have relatively large flowers that promote outcrossing—resulting in the distinctive hybrid, E. ×treleasianum, which has very notably large, pink flowers. Hybrids formed with other sympatric taxa are less obvious, but can be detected by both reduced seed set and interme­diate morphology.

Epilobium adenocaulon Haussknecht var. cinerascens (Piper) M. Peck is an illegitimate name that pertains here.