37. Galium odoratum (Linnaeus) Scopoli, Fl. Carniol., ed. 2. 1: 105. 1771.
车轴草 che zhou cao
Asperula odorata Linnaeus, Sp. Pl. 1: 103. 1753.
Herbs, perennial, from slender and elongated rhizomes. Stems erect, 10-50 cm tall, 4-angled, glabrous and smooth except hispidulous at nodes. Leaves in whorls of 6-10, sessile or petiole to 1 mm; blade drying papery, oblanceolate, oblong-lanceolate, or narrowly elliptic, (6-)15-50(-65) × (3-)4.5-15(-17) mm, length/breadth index ca. 4, glabrous except antrorsely aculeolate on margins and with antrorse microhairs on upper side and sometimes on abaxial midrib, base acute to cuneate, margins flat, apex acute or usually obtuse then abruptly mucronate; vein 1. Inflorescences terminal, with several- to many-flowered cymes; axes glabrous, smooth; bracts none or leaflike, 1-3 mm; pedicels 1-4 mm. Ovary ellipsoid to obovoid, ca. 0.8 mm, densely hispidulous. Corolla white or bluish white, ± broadly funnelform, 4.5-6.5 × 3-7 mm, glabrous, lobed for ca. 1/2; lobes 4, triangular-spatulate, acute. Mericarps subglobose, 2-2.5 mm, with dense uncinate trichomes 1-1.2 mm. Fl. and fr. Jun-Sep.
Mountain forests; 1500-2800 m. Gansu, Heilongjiang, Jilin, Liaoning, Ningxia, Qinghai, Shandong, Shanxi, Sichuan, Xinjiang [Japan, Korea, Russia; NW Africa, SW Asia, Europe; introduced in North America].
Dried plants of Galium odoratum have a sweet coumarine odor, which is still evident on herbarium specimens; its name refers to this. On account of its funnelform corollas (with the tube ± as long as the lobes), G. odoratum usually has been treated as a member of Asperula. As shown by Ehrendorfer et al. (Fl. Iranica 176: 183. 2005) and verified by DNA-analytical studies, it belongs to G. sect. Hylaea and is closely related to G. asperuloides and G. hoffmeisteri. Without flowers it is difficult to separate, particularly from the former with more narrow leaves, but generally G. odoratum is more robust. As a constant element of temperate deciduous forests (often with Fagus), it has an extensive but rather disjunct distribution area throughout Eurasia, with diploid cytotypes in E Asia, replaced by tetraploids in Europe.