Chamaenerion angustifolium (L.) Scop., 1772

Luo, Yike & Xie, Lei, 2023, A checklist of Onagraceae in the Pan-Himalaya region, Phytotaxa 597 (4), pp. 245-268 : 247-249

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

Figures

FIGURE 2. Field photographs of Chamaenerion and Circaea.A:Chamaenerion angustifolium.B: Chamaenerion conspersum. C: Circaea alpina subsp. imaicola. D: Circaea cordata. E: Circaea repens. Photographed by Y.K. Luo & L. Xie.