20. Rubia ovatifolia Z. Ying Zhang ex Q. Lin, J. Wuhan Bot. Res. 24: 212. 2006.
卵叶茜草 luan ye qian cao
Vines, herbaceous, perennial, climbing; stems to 1.5 m, slender, quadrangular, glabrous and smooth to sparsely aculeolate. Leaves in whorls of 4; petiole (1.5-)2.5-5.5(-13) cm; blade drying thinly papery, adaxially green, abaxially pale green, ovate-cordiform to suborbicular-cordiform, on lateral branches sometimes ovate, (2-)4-7(-12) × (1-)2-5(-6.5) cm, length/ breadth index 1.5-2, glabrous to scaberulous, base cordulate to cordate, margins retrorsely ciliolate or smooth, apex caudate-acuminate, rarely ± obtuse; principal veins 5, palmate. Inflorescence thyrsoid, leafy, with terminal and axillary, few- to many-flowered cymes; axes glabrous and smooth or sparsely aculeolate; bracts linear or lanceolate-linear, 1-3.5 mm; pedicels 1-3 mm. Ovary ca. 1 mm, glabrous. Corolla whitish or pale yellow, subcampanulate, glabrous; tube 0.8-1 mm; lobes spreading and somewhat bent, ovate to lanceolate-triangular, ca. 1.4 mm, caudate. Mericarp berry black at maturity, 4-5 mm in diam. Fl. Jul, fr. Oct-Nov.
● Sparse forests or thickets on mountains; 1700-2200 m. Gansu, Guizhou (Bijie), ?Hubei, Hunan, Shanxi, Sichuan, Yunnan, Zhejiang (Changhua).
This name was first published by Z. Ying Zhang (Fl. Tsinling. 1(5): 15, 420. 1985) but not validly so because two gatherings were designated as types (Vienna Code, Art. 37.2). This was corrected in the above citation from 2006.
We have not seen authentic material of Rubia ovatifolia, but there are good drawings in the Tsinling flora and in H. S. Lo (in FRPS 71(2): 307, t. 68, f. 1-5. 1999). This and the description show that it belongs to the taxa of R. ser. Cordifoliae and the group with campanulate flowers, as R. alata or R. podantha. This differential character, so far rather neglected, separates these taxa, e.g., from R. argyi. Nevertheless, one has to expect intermediates that link R. ovatifolia with R. sylvatica and R. cordifolia s.s. (see the latter for additional comments).
H. S. Lo (loc. cit.: 306) differentiated two varieties of doubtful status: the ranges of petiole length indicated can be found on a single specimen among the principal and the lateral stems; the descriptions do not specify which leaves to measure. The so-called "var. oligantha" may be a depauperate or very young specimen of this or some other species. The name was not validly published because no type was indicated and because the name of the species to which it was assigned was not validly published (Vienna Code, Art. 37.1 and Art. 43.1, respectively). Without further study it should not be validated.