Epilobium williamsii Raven

Herbs perennial, clumped or matted, with fleshy, elongated soboles 1.5-7 cm that leave brown basal scales. Stems 4-17(-25) cm tall, usually branched from base or simple, strigillose and glandular above, subglabrous or sparsely strigillose below with faint raised strigillose lines decurrent from margins of petioles. Leaves crowded, subleathery, sessile or petioles to 2 mm; cauline blade ovate to elliptic-ovate, 0.7-2.2 × 0.3-1 cm, subglabrous except for sparsely strigillose margin and midvein, base subrounded to broadly cuneate or subcordate, margin serrulate with 6-18(-26) teeth per side, apex acute to subacuminate. Inflorescence and flowers nodding to suberect. Sepals 3-4.5 mm. Petals rose-purple, 5-6.5 mm. Stigma capitate, entire. Capsules 3.5-5(-6) cm, sparsely strigillose; pedicels 4-10 mm. Seeds gray-brown, 0.9-1(-1.2) mm, finely papillose, with short chalazal collar; coma white, detaching easily. Fl. Jul-Aug, fr. Aug-Sep. Chromosome number unknown.

Himalaya (Nepal to Bhutan), S.E. Tibet.

Qinghai, Sichuan, Xizang, Yunnan [India, Myanmar, Nepal].

3500-4800 m

Open alpine meadows, moist places by streams, or on gravel banks of glacial lakes in high mountains; (2900-)3400-4900 m.