Epilobium montanum L.

Perennial herb (5)–20–100 cm tall, often much-branched, in autumn producing short ± horizontal stolons from base of plant; stolons terminating in fleshy or leafy buds below or above ground; flowering stems erect; plants covered with erect or appressed eglandular hairs. Lvs opposite below, alternate in the infl., dark green, strigillose, especially along the veins and margins, 3–8 × 1.5–3.4 cm, irregularly serrate, narrowly-ovate or ovate; apex acuminate or acute; base broadly cuneate to truncate; petiole 1–6 mm long. Infl. nodding, with glandular hairs and strigillose. Fls erect. Ovary 2–3 cm long. Floral tube 1.2–2 mm deep, with a conspicuous ring of long hairs inside. Sepals keeled, 5–6.5 × 1.2–1.7 mm. Petals rose-purple, 7.5–10 × 4–5.5 mm. Filaments of the longer stamens 3.5–5.5 mm long. Style 3.5–5.5 mm long, rosy purple or white, glabrous or nearly so; stigma deeply 4-lobed, the lobes 1.2–1.8 mm long. Capsule 4–8 cm long; fruiting pedicel 0.8–1.5 cm long. Seeds 1–1.2 × 0.45–0.55 mm, obovoid, coarsely papillose.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]