47. Galium serpylloides Royle ex J. D. Hooker, Fl. Brit. India. 3: 207. 1881.
隆子拉拉藤 long zi la la teng
Herbs, perennial, ascending, 3-10 cm tall. Rootstock woody, rhizomatous. Stems 4-angled, branched, shortly pubescent. Leaves in whorls of 4(or ?5), sessile; blade drying papery, ovate or elliptic, 4-6 × 2.5-4 mm, glabrous or sparsely hirtellous, base rounded, margins thinly revolute, usually with antrorse microhairs, apex obtuse or slightly acute; principal vein 1 (or with 2 inconspicuous side veins). Inflorescences terminal and in axils of upper leaves, with cymes 5-8 mm, few or usually 3-flowered; pedicels 1-2 mm. Flowers hermaphroditic to subdioecious. Ovary appressed hairy. Corolla yellowish green, rotate, ca. 2 mm in diam.; lobes 4, ovate-triangular, acute. Mericarps up to 2 mm, with straight lanate hairs. Fl. and fr. Jun-Sep.
Mountain slopes; 3600-3800 m. Xizang (Lhünzê) [India, Nepal].
Originally, Galium serpylloides was very broadly circumscribed as a species widely distributed throughout the whole Himalayan range. But a critical taxonomic analysis of the group by Schönbeck-Temesy and Ehrendorfer (Pl. Syst. Evol. 155: 77-87. 1987) revealed five vicarious and geographically well-separated species from Kashmir in the west to Nepal in the east: G. gymnopetalum Ehrendorfer & Schönbeck-Temesy, G. lakulense Ehrendorfer & Schönbeck-Temesy, G. serpylloides s.s., G. saipalense Ehrendorfer & Schönbeck-Temesy, and G. nepalense Ehrendorfer & Schönbeck-Temesy. The above cited locality from E Xizang, Lhünzê, published in FRPS (71(2): 228. 1999), is much further to the east, i.e., SE of Lhasa and NE of Bhutan. We have neither seen authentic material from this nor from other Xizang and Charme province collections in the herbarium BM (e.g., Ludlow, Sheriff & Taylor 6390). At the moment, it is not possible to decide whether they correspond to one of the above mentioned species of the G. serpylloides group, or the related G. glandulosum group, or represent a still undescribed taxon. Therefore, we provisionally classify these SE Xizang populations under G. serpylloides s.l.
Characteristic morphological features of the Galium serpylloides group are the whorls of 4 leaves and leaflike stipules, the trend toward palmate leaf veins and sexual differentiation of flowers, and the change from hooked to straight fruit hairs. All this suggests relationships with members of G. sect. Platygalium s.l., as the G. morii group (in particular G. nankotaizanum) or the G. elegans group. These trends reappear (probably as a homoplasy?) in the W North and South American G. sect. Lophogalium K. Schumann, evidently derived from ancestors similar to G. sect. Platygalium s.l.