28. Epilobium montanum Linnaeus, Sp. Pl. 1: 348. 1753.
Chamaenerion montanum (Linnaeus) Scopoli
Herbs with short, basal stolons terminating in fleshy or leafy rosettes at, or just below, ground level. Stems erect, terete, (5–)20–95 cm, often well branched, especially distally, densely strigillose proximal to inflorescence, without decurrent lines, mixed strigillose and glandular puberulent distally. Leaves opposite proximal to inflorescence, alternate distally, petiole 1–6 mm; blade dark green, narrowly ovate to ovate, 3–8 × 1.5–3.4 cm, subequal to internodes, base broadly cuneate to truncate, margins irregularly serrulate with 20–30 teeth per side, veins prominent, 3–5 per side, apex acuminate to acute, surfaces strigillose, especially along veins and margins; bracts much reduced. Inflorescences nodding to erect, racemes or loose panicles, strigillose and glandular puberulent. Flowers erect; buds 4–5 × 1.5–3 mm; pedicel 2–18 mm; floral tube 1.2–2 × 1.5–2.5 mm, conspicuous ring of spreading hairs at mouth inside; sepals often flushed red, keeled, 5–6.5 × 1.2–1.7 mm, abaxial surface strigillose and glandular puberulent; petals rose-purple, obcordate, 7.5–10 × 4–5.5 mm, apical notch 2.7–4.2 mm; filaments light pink, those of longer stamens 3.5–5.5 mm, those of shorter ones 1.5–2.4 mm; anthers yellow, 1–1.2 × 0.5–0.6 mm; ovary 20–30 mm, strigillose and glandular puberulent; style rose-purple to white, 3.5–7.5 mm, glabrous or with scattered long hairs near base, stigma deeply 4-lobed, 1.5–2 × 2.5–4 mm, lobes 1.2–1.8 mm, exserted beyond or, sometimes, surrounded by anthers. Capsules 40–80 mm, surfaces strigillose and glandular puberulent; pedicel 8–20 mm. Seeds obovoid, 1–1.2 × 0.4–0.5 mm, chalazal collar inconspicuous, 0.6–0.8 mm wide, brown, surface coarsely papillose; coma readily detached, dull white, 5–6 mm. 2n = 36.
Flowering Jul–Aug. Moist rocky banks, gravelly slopes, open woods, disturbed or waste areas; 0–150[–1500] m; introduced; B.C., Nfld. and Labr. (Nfld.); Maine; Europe; Asia; introduced also in Pacific Islands (New Zealand).
Epilobium montanum is native and widely distributed throughout Europe and in Asia at least as far east as the Ural Mountains and the Caucasus, and in Japan (A. W. Lievens and P. C. Hoch 1999). It also is questionably naturalized on Campbell Island, New Zealand (P. H. Raven and T. E. Raven 1976). Although E. montanum was first collected in 1894 in the vicinity of St. John’s, Newfoundland, and clearly naturalized in that area, it does not appear to have spread appreciably in eastern North America, unlike European adventives such as E. hirsutum or E. parviflorum. The collection by F. C. Seymour in 1971 in Maine may be an independent introduction. Collections of E. montanum in the University of British Columbia Botanical Garden in Vancouver appeared to have been ephemeral, but more recent collections in ruderal areas in that region suggest that it has naturalized there. Like other European introductions, E. montanum has the BB chromosome arrangement (S. R. Seavey and P. H. Raven 1977).