1. Chamerion latifolium (Linnaeus) Holub, Folia Geobot. Phytotax. 7: 86. 1972.
宽叶柳兰 kuan ye liu lan
Epilobium latifolium Linnaeus, Sp. Pl. 1: 347. 1753; Chamaenerion latifolium (Linnaeus) Franchet & Lange; E. changaicum Grubov; E. kesamitsui Yamazaki.
Herbs perennial, erect, clumped, with a thick woody rhizome and wiry mass of roots. Stems 12-35 cm tall, glabrous below to sparsely or rarely densely strigillose on upper stem and inflorescence. Leaves sessile or petioles to 2 mm; basal leaf blade brown, triangular-ovate, 5-10 mm, submembranous; cauline blade green or pale green, elliptic or ovate to lanceolate-elliptic, 2-5(-8) × 0.6-1.7(-2.6) cm, subglabrous or strigillose, especially on veins, lateral veins obscure, 3 or 4 per side, base cuneate or sometimes subobtuse, margin subentire to remotely punctate-denticulate with 4-7 teeth, apex obtuse or acuminate. Bracts ca. 1/2 as long as cauline leaves, foliaceous. Inflorescence sparsely to moderately strigillose. Flowers erect in bud, nodding at early anthesis. Sepals 1-1.6 cm × 1.5-3.5 mm. Petals rose-purple or pink, 1-2.4(-3.2) cm × 7-15(-23) mm. Ovary purplish green, 1-2 cm, densely canescent; style 3.5-8 mm, glabrous. Capsules 2.5-8 cm, strigillose; pedicels 1.2-2.5 cm. Seeds 1.2-2.1 × 0.4-0.6 mm, irregularly low-reticulate, with distinct chalazal collar 0.1-0.12 mm; coma tawny or dingy, 9-15 mm, not readily deciduous. Fl. Jun-Aug, fr. Aug-Oct. 2n = 36, 72.
Moist gravelly areas along rivers and in mountains; 1600-5200 m. Qinghai, Xinjiang, Xizang, NW Yunnan [Afghanistan, Bhutan, India, Japan, Mongolia, Nepal, Pakistan, Russia (Amur region, Siberia), Tajikistan; C and SW Asia, Europe, North America (including Greenland)].
Populations of this species occur mainly in two disjunct areas in China: the Tian Shan-Altay-Pamir region of Xinjiang, and the E Himalayan region of Xizang and Yunnan (with one outlier in Qinghai). There are some morphological differences in pubescence, leaf margin and veins, and pollen size and number of pores between populations from the two regions, which may be correlated with ploidy levels, those from Xinjiang apparently being diploid and those from SW China being tetraploid. However, more chromosome counts and further careful analyses of populations are needed to clarify this situation.