金剑草 jin jian cao

Rubia cordifolia Linnaeus var. longifolia Handel-Mazzetti; R. lanceolata Hayata.

Climbers and vines, herbaceous, perennial; stems to 4 m, quadrangular, 4-ridged, or usually 4-winged at least when older with wings to 1.5 mm wide, glabrous or hirtellous-puberulent at nodes, retrorsely aculeolate. Leaves and leaflike stipules in whorls of 4, often unequal (stipules smaller); petiole 0.2-10 cm, on principal axes longer than on lateral ones, those of stipules often shorter or even lacking; blade drying thinly leathery, linear-lanceolate or narrowly lanceolate, 3.5-9 × 0.4-2 cm, with length/breadth index above 3, glabrous and smooth or sometimes sparsely scaberulous, base rounded to cordulate, margin thinly revolute and usually aculeolate, apex acute; principal veins palmate, 3(or 5) with lateral veins sometimes weakly evident. Inflorescences thyrsoid, paniculate, with terminal and axillary, many-flowered cymes; axes smooth to aculeolate, ridged to thinly winged; bracts elliptic to lanceolate-elliptic, 0.8-3 mm; pedicels 1-4 mm. Ovary ca. 0.7 mm, smooth. Corolla white, pale yellow, or greenish, campanulate, fused base 0.5-1 mm, glabrous; lobes triangular to lanceolate, 1.2-1.5 mm, apex caudate-acuminate. Mericarp berry black, 5-7 mm. Fl. May-Aug, fr. Aug-Nov.

Forest margins on mountain slopes, thickets; 600-2000 m. Provinces south of the Chang Jiang, east to Taiwan, west to Sichuan, north to C Henan and S Shanxi: Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang [Nepal].

Rubia alata, an obvious member of R. ser. Cordifoliae, is here treated in the sense of H. S. Lo (in FRPS 71(2): 312, t. 70, f. 1-6. 1999), which may or may not correspond to its original application and its type. Accordingly, it is mainly characterized by relatively narrow leaves, petioles frequently bent near the base of the blade, stem angles with thin ridges to narrow or remarkably well-developed wings, and paniculate inflorescences, small flowers, and black fruit similar to other species of the R. cordifolia group (see additional comments under that species). The protologue of R. alata does not address the shape of the leaves and describes the stems as winged or not. This suggests the possibility that that the type’s leaves are not markedly narrower and its stems not more markedly winged than those of R. cordifolia and related species. Rubia alata was not treated by Deb and Malick (Bull. Bot. Surv. India 10(1): 1-16. 1968) for India, nor by Long (Fl. Bhutan 2(2): 823-825. 1999) for Bhutan. The Kew Rubiaceae checklist (Govaerts et al., World Checkl. Rubiaceae; http://www.kew.org/wcsp/rubiaceae/; accessed on 15 Sep 2010) considers it to be a synonym of R. cordifolia but gives no source for this conclusion. From the relatively abundant herbarium material studied and the rather narrow species concept used in the present treatment, we believe that it is justified to distinguish R. alata sensu H. S. Lo and R. cordifolia s.s.

Rubia lanceolata from Taiwan is provisionally referred here as a synonym to R. alata. Some of the named varieties of R. cordifolia may also belong to this species but a clarification is impossible with our present insufficient knowledge of R. ser. Cordifoliae. The herbarium name "R. cordifolia var. stenophylla Franchet" does not appear to have ever been published anywhere.

The numerous collections from the Biodiversity Survey of the Gaoligong Shan area in Yunnan have revealed the common occurrence of Rubia alata and the presence of rare R. siamensis together with many populations, which link these two quite different taxa. These intermediates exhibit most varied differential character recombinations of the two species with respect to leaf shape, from broadly lanceolate to cordate (length/breadth index below 3) or from small triangular and sessile stipules to fully leaflike elements with long petioles. In addition, new characters appear, such as greenish to yellowish fruit colors. The suspicion that all this is the result of hybridization needs support by further studies.