1.1. Chamaenerion angustifolium (L.) Scop. (Fig. 2A). ≡ Epilobium angustifolium L. ≡ Chamerion angustifolium (L.) Holub (1972: 86). Lectotype (designated by Raven 1962a):—Habitat in Europea boreali, Herb. Linn. No. 486.1 (LINN digital image). Distribution: —Widely distributed in the Pan-Himalaya region. Note: — Chamaenerion angustifolium have two subspecies, diploid (n = 18) C. angustifolium subsp. angustifolium and tetraploids (n = 36) C. angustifolium subsp. circumvagum (Mosquin 1966: 167) Moldenke (1973: 289). Triploids occasionally occurred in diploid and tetraploid contact zone (Sabara et al. 2013). These two subspecies are delimited by morphology (Mosquin 1966) as the following key. Key to subspecies of Chamaenerion angustifolium in the Pan-Himalaya region 1 Midvein glabrous on both side of leaves, (3–)7–14(–18.5) cm, base obtuse or subrounded, margin subentire, subsessile; petals 0.9–1.9 cm ...................................................................................................................... 1.1a. C. angustifolium subsp. angustifolium - Midvein usually pubescent on both side of leaves, (6–) 9–23 cm, base cuneate, margin denticulate, petioles 2–7 mm; petals 1.5–2.5 cm ................................................................................................................................... 1.1b. C. angustifolium subsp. circumvagum

Published as part of Luo, Yike & Xie, Lei, 2023, A checklist of Onagraceae in the Pan-Himalaya region, pp. 245-268 in Phytotaxa 597 (4) on pages 247-249, DOI: 10.11646/phytotaxa.597.4.1, http://zenodo.org/record/7958600