高黎贡山茜草 gao li gong shan qian cao

Herbs, perennial, sprawling or twining; stems to 2 m, branched, quadrangular, glabrous and smooth or sparsely retrorsely aculeolate. Leaves and leaflike stipules in whorls of never more than 4; petiole (1-)2-4(-6) mm; blade when drying blackening, subleathery, lower side somewhat brighter than upper, linear-lanceolate, lanceolate, or lanceolate-oblong, often somewhat falcate, 20-40 × 2-8 mm, base cuneate to acute, margins and vein adaxially somewhat retrorsely aculeolate or smooth, apex acute or shortly acuminate; principal vein 1, 2 basal lateral veins very weak, often hardly visible. Inflorescences thyrsoid, with axillary, somewhat narrowly elongate, many-flowered cymes; peduncles glabrous, 3-6 mm; bracts small, linear-lanceolate, 0.5-3 mm; pedicels 1-6 mm. Ovary inferior, obovoid, ca. 0.8 mm. Corolla yellowish green, white, or purple, rotate, fused part 0.2-0.5 mm; lobes 5, ovate-triangular, 1.2-1.5 mm, shortly acuminate. Mericarp berry blackening, globose, 3-5 mm in diam. Fl. May-Jun, fr. Jul-Aug.

● Subtropical montane evergreen broad-leaved forests; 2400-3000 m. Yunnan (Gaoligong Shan region).

This new species is strongly reminiscent of certain taxa of Galium in habit. Its technical features (as well as DNA data) clearly place it into Rubia. In spite of its narrow leaves with only 2 weak lateral veins, it appears to belong to R. sect. Oligoneura. It forms an obviously related group with R. truppeliana from the mountains of Shandong. Main differences are the leaf whorls never with more than 4 elements, the shorter leaf petioles and peduncles, and the smaller flowers. There is remarkable variation in leaf shape and flower color, as documented by the numerous specimens available from the Gaoligong Shan region, where R. pseudogalium may be endemic.