卵叶轮草 luan ye lun cao

Asperula platygalium Maximowicz, Bull. Acad. Imp. Sci. Saint-Pétersbourg 19: 284. 1874.

Herbs, perennial, from thin creeping rhizomes. Stems erect, 20-35 cm tall, with 4 thickened angles, smooth, at nodes glabrous or hispidulous. Leaves in whorls of 4(-6), subsessile, with petiole up to 2 mm; blade drying papery to leathery, elliptic or elliptic-oblong to ovate, (12-)20-25(-28) × (7-)10-11(-15) mm, glabrous or hirtellous to hispidulous along principal veins, ± abruptly narrowed into short petiole, margins antrorsely ciliolate, apex obtuse to subacute; principal veins 3-5, palmate. Inflorescences umbel-like thyrsoid and many-flowered panicles with terminal and lateral cymes from uppermost leaf axils; peduncles smooth and glabrous; bracts narrowly oblanceolate or elliptic to ligulate, 1-3 × 0.5-1.5 mm; pedicels 0.5-1.5 mm. Ovary ellipsoid, ca. 0.8 mm, glabrous. Corolla white, funnelform, with tube ± as long as lobes, 4-5 mm in diam.; lobes 4, elliptic-oblong. Mericarps ovoid, 1.7-2.8 mm, glabrous and smooth. Fl. and fr. Jul-Sep.

Open forests on mountain slopes; ca. 1700 m. Heilongjiang, Jilin, Shanxi [Korea, Russia].

Galium platygalium is closely related to G. maximoviczii (see there) but has larger flowers and whorls of opposite leaves and leaflike stipules with 4 or more (rarely up to 6) elements. Because of their slightly elongated, fused corolla base, the two species in the older literature were placed into the genus Asperula, where they had no other close relatives. In spite of their increase in leaf whorl elements, the two species have been placed by Ehrendorfer et al. (Fl. Iranica 176: 175. 2005) into G. sect. Platygalium s.l. Though this section normally is characterized by leaf whorls with only up to 4 elements, this placement may be justified because the two species correspond otherwise quite well, as in habit, inflorescences, and leaves (with 3-5 palmate principal veins).

Furthermore, Galium platygalium and G. maximoviczii exhibit similarities with Microphysa elongata (see p. 216), also with a well-developed corolla tube but with leaves in whorls of only 4 and only 1 main vein. Thus, the monotypic "genus" Microphysa, maintained here, is another obvious member of G. sect. Platygalium.