13. Galium dahuricum Turczaninow ex Ledebour, Fl. Ross. 2: 409. 1844.
大叶猪殃殃 da ye zhu yang yang
Herbs, perennial, from a slender reddish rootstock. Stems erect to ascending, weak to procumbent and often climbing, sometimes up to 2.5 m, 4-angled, sparsely to densely retrorsely aculeolate along angles and at nodes, rarely ± glabrescent. Leaves on main stems in whorls of 5 or 6, subsessile; blade drying papery, of very variable shape, from obovate and elliptic-oblong to narrowly oblanceolate, (11-)15-40(-55) × (2-)3-10(-14), sparsely to densely retrorsely aculeolate adaxially along midrib, abaxially, and along flat to thinly reflexed margins, base acute to cuneate, apex acute to obtuse and mucronate; vein 1. Inflorescences paniculate, with axillary and terminal, several- to many-flowered, usually very lax and up to 7 cm long cymes; axes filiform and often flexuous, sparsely aculeolate to glabrous; bracts few, lanceolate; pedicels slender, in flower 2-5 mm. Ovary obovoid, ca. 0.8 mm, with dense spreading or appressed undeveloped trichomes, or glabrous. Corolla white or pale green, rotate, of quite different sizes, (1-)1.5-3(-4) mm in diam., glabrous; lobes 4, triangular, obtuse to acute or minutely apiculate. Mericarps ellipsoid, ca. 2 mm, with appressed or spreading and uncinate trichomes (0.3-0.5 mm), tuberculate to completely glabrous and smooth, on pedicels elongating to 10 mm or more. Fl. Jun-Sep, fr. Jul-Nov.
Humid forests, thickets, ditch sides, grasslands, meadows; 200-3400 m. Fujian, Gansu, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan, Zhejiang [Japan, Korea, Russia].
Within Galium sect. Trachygalium and the extremely polymorphic species group of G. asperifolium (see there) Cufodontis (Oesterr. Bot. Z. 89: 239-243. 1940), Yamazaki (Fl. Japan 3a: 206-240. 1993), and W. C. Chen (in FRPS 71(2): 255-258. 1999) differentiated the closely related taxa G. dahuricum (in FRPS as "G. davuricum," the spelling used in the protologue by Ledebour), G. tokyoense, G. pseudoasprellum, and G. manshuricum mainly according to the lack (in the two former) and the presence (in the two latter) of appressed or spreading uncinate trichomes on the mericarps. As this character apparently often varies within populations of these taxa, the present treatment relies on the much more stable feature of slender, filiform, and ± flexuose vs. more stiff and divaricate peduncles and pedicels. The former state characterizes G. dahuricum (including G. manshuricum and G. pseudoasprellum), the latter G tokyoense. This species assembly has its distribution center in E Asia but extends with G. asprellum Michaux s.s. into E North America.
Galium pseudoasprellum was accepted as a species by Cufodontis (loc. cit.: 237-238), W. C. Chen (loc. cit.: 254-255), and Yamazaki (loc. cit.: 238), and the latter two also maintained G. niewerthii. In our opinion and because of their similar inflorescences, both taxa should be regarded as synonyms of G. dahuricum, the former under var. lasiocarpum, the latter under var. dahuricum. Even if we have not seen authentic specimens of G. niewerthii, all of its characters listed fall within the limits of G. dahuricum; thus, we regard it as a glabrous-fruited form of that variable species. So far, G. comarii has been a badly understood taxon (see Cufodontis, loc. cit.: 241; Lauener, Notes Roy. Bot. Gard. Edinburgh 32: 107. 1972; Mill, Edinburgh J. Bot. 53: 193-213. 1996). Because of its slender inflorescence, extremely long pedicels, and rugose fruit mentioned in the protologue, it can now be safely assigned as another synonym of G. dahuricum var. dahuricum.
The following infraspecific taxa of Galium dahuricum (and G. pseudoasprellum), accepted by Cufodontis (loc. cit.: 237-238, 243-244) and W. C. Chen (loc. cit.), are keyed and listed here for comparison.
