东南茜草 dong nan qian cao

Galium argyi H. Léveillé & Vaniot, Bull. Soc. Bot. France 55: 58. 1908; Rubia akane Nakai; R. akane var. erecta Masamune; R. chekiangensis Deb.

Vines, herbaceous, perennial (rarely erect in mountains of Taiwan: Rubia akane var. erecta); stems probably to 2 m or more, quadrangular to narrowly 4-winged especially when older, glabrous to pilosulous, retrorsely aculeolate sometimes becoming smooth with age. Leaves nearly exclusively in whorls of 4, equal or sometimes unequal; petiole 0.5-5 cm; blade when drying often blackening, ± thickly papery, suborbicular-cordiform, broadly ovate-cordiform, or oblong-suborbicular, (1-)2-4.5(-5) × (1-)1.5-3.5(-4) cm, length/breadth index 1-1.8, glabrous or sparsely to densely pilosulous or hirtellous, scaberulous, base cordate to cordulate, margins sparsely to densely retrorsely aculeolate, apex cuspidate to apiculate; principal veins palmate, 5 or 7, veins usually ± impressed and tertiary venation visible. Inflorescences thyrsoid, paniculate, with terminal and axillary, many-flowered cymes, axes aculeolate, glabrous to pilosulous; bracts lanceolate or lanceolate-elliptic, 1-4 mm; pedicels rather stout, 1-2.5 mm. Ovary ca. 0.8 mm, smooth. Corolla yellowish-greenish to white, rotate to bell-shaped, glabrescent, fused base 0.5-0.7 mm; lobes lanceolate, 1.3-1.4 mm, spreading to ± reflexed. Mericarp berry black, subglobose 5-7(-9) mm in diam. Fl. Jul-Oct, fr. Aug-Nov.

Forest margins, thickets, fences at village sides; 300-3400 m. Anhui, Fujian, Guangdong, Guangxi, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Taiwan, Zhejiang [Japan, Korea].

Rubia akane is here treated as a synonym of R. argyi, following the Kew Rubiaceae checklist (Govaerts et al., World Checkl. Rubiaceae; http://www.kew.org/wcsp/rubiaceae/; accessed on 15 Sep 2010), Yamazaki (Fl. Japan 3a: 232. 1993), and H. S. Lo (in FRPS 71(2): 316. 1999). The recent Taiwanese flora (T. Y. A. Yang, Fl. Taiwan, ed. 2, 4: 322. 1998), however, continues to regard R. akane as a separate species and characterizes it by white flowers, whereas R. argyi generally is regarded as yellowish-greenish flowering. Aside from corolla color, no differential characters are apparent between the two taxa. However, in addition to the typical climbing and vinelike "var. akane" in Taiwanese localities below 2000 m, at higher elevations and more open habitats of the Taiwanese mountains, there is an upright growing type called R. akane var. erecta, which seems to be endemic. As a species it has been called R. nankotaizana Masamune (Hokuriku J. Bot. 2: 40. 1953). If it is actually conspecific, it should be transferred as a variety to R. argyi.

Rubia argyi belongs to R. ser. Cordifoliae and is well illustrated in the FRPS treatment by H. S. Lo (loc. cit.: 317, t. 71, f. 1-6). With the differential characters available (mainly the relatively broad and short leaves with veins impressed), it can be separated rather clearly from the very closely related members R. cordifolia s.l. (or better R. cordifolia agg., see there). To lump it with R. cordifolia (e.g., Z. Ying Zhang, Fl. Tsinling. 1(5): 14. 1985) does not appear justified. Within the R. cordifolia agg. R. argyi comes closest to R. sylvatica, from which it deviates primarily by its larger leaves, partly in whorls of more than 4. Rubia ovatifolia can be separated by its definitely campanulate flowers with a fused base of 0.8-1 mm. For additional comments see under R. cordifolia.