四川拉拉藤 si chuan la la teng

Herbs, perennial, from filiform rhizomes ascending to erect, ca. 30 cm tall. Stems single, strongly branched from base, with 4 prominent and whitish angles, glabrous and smooth, only slightly aculeolate at nodes. Middle stem leaves and leaflike stipules in whorls of 4-6; blade drying papery and greenish-brownish, lanceolate, (12-)15-20(-25) × (3-)4-6(-7) mm, glabrous but on adaxial side near margins with antrorse appressed microhairs, on ± flat margins retrorsely (sometimes also somewhat antrorsely) aculeolate, subsessile and gradually narrowed into base, largest breadth near middle, apex cuspidate with hyaline point; principal vein 1. Inflorescences broadly ovate, many flowered, cymes terminal and lateral, 2.5-5 cm, slender, leafy and bracteate to last branches, ± divaricate; axes glabrous; peduncles 1.5-2 cm; pedicels 0.5-5 mm. Flowers hermaphroditic. Ovary obovoid, 0.5-0.8 mm, with appressed curved hairs. Corolla dried reddish brown, rotate, 1.5-2 mm in diam.; lobes 4, triangular, cuspidate. Mericarps ovoid, 1.8-2.5 mm, with ± spreading uncinate trichomes 0.2-0.3 mm. Fl. Jul-Aug, fr. Aug-Sep.

● Mountain forests; 3200-4000 m. Sichuan (Daocheng).

Up to now, only two collections of Galium sichuanense are known from the type locality. The new species is morphologically isolated and not closely related to any other taxon of the genus. Its character profile, particularly its perennial, hemicryptophytic growth form, the partly retrorsely aculeolate leaf margins, and the fruit with uncinate trichomes, designates it as a member of G. sect. Trachygalium, but there are also features reminiscent of G. sect. Hylaea (cf. Ehrendorfer et al., Fl. Iranica 176: 181. 2005). Nevertheless, the combination of the branching pattern, the membranous leaves, the predominant glabrescence, the leafy inflorescences, and the small flowers separate it clearly from all other members of the two sections.

Another isolated and apparently relict species from E Asia has to be compared with Galium sichuanense, the Japanese G. kikumugura (see also under G. hoffmeisteri). The two share the leaves in whorls of 4-6, the small flowers, and the hooked fruit trichomes. In contrast, the habit and the somewhat antrorsely rough or even aculeolate leaf margins of G. kikumugura are reminiscent of G. bungei (G. sect. Platygalium). Unique characters of G. kikumugura are the very few-flowered cymes on long peduncles with a single bract and the elongate, curved mericarps. Its taxonomic placement within Galium also is uncertain.