58. Galium trifloriforme Komarov, Trudy Imp. S.-Peterburgsk. Bot. Sada. 18: 428. 1901.
拟三花拉拉藤 ni san hua la la teng
Herbs, perennial, from elongated rhizomes. Stems procumbent to erect, (10-)25-40(-65) cm tall, 4-angled, mostly slightly retrorsely aculeolate, hirtellous at nodes. Leaves on main stems in whorls of up to 6(-8), subsessile; blade drying papery, blackish or green, narrowly obovate to oblanceolate, (12-)18-28(-50) × (3-)5-10(-15) mm, with sparse antrorse microhairs adaxially, moderately retrorsely aculeolate abaxially on vein and at leaf margins, base acute to cuneate, margins flat to thinly revolute, apex acute, obtuse, or rounded and abruptly mucronate; vein 1. Inflorescences with axillary and terminal cymes on upper 2 or 3 nodes, mostly 2-8-flowered; axes glabrous, smooth; bracts none or few, narrowly elliptic to narrowly lanceolate, 2-5 mm; pedicels ca. 1.5 mm. Ovary obovoid, ca. 0.5 mm, densely hispidulous with undeveloped trichomes. Corolla white or pale green, rotate, 1.5-2 mm in diam., glabrous; lobes 4, triangular, acute. Mericarps ellipsoid, 1.5-2.5 mm, with dense uncinate trichomes ca. 1 mm, fruiting pedicels divaricate and elongating to 10 mm. Fl. and fr. Jul-Sep.
Mountain forests, open fields; 2200-3400 m. Heilongjiang, Jilin, Nei Mongol, Qinghai [Japan, Korea, NE Russia].
Galium trifloriforme is a variable and problematic taxon from NE Asia. It was either accepted as a separate species (e.g., by Pobedimova et al., Fl. URSS 23: 303. 1958; Yamazaki, Fl. Japan 3a: 239. 1993) or was treated as a synonym of G. triflorum (see Cufodontis, Oesterr. Bot. Z. 89: 236-237. 1940) or of G. hoffmeisteri (e.g., W. C. Chen in FRPS 71(2): 230. 1999, as G. asperuloides subsp. hoffmeisteri; Govaerts et al., World Checkl. Rubiaceae; http://www.kew.org/wcsp/rubiaceae/; accessed on 15 Sep 2010). It differs from the very close typical G. triflorum by its more condensed inflorescence with cymes terminal and on the upper 1 or 2(or 3) nodes, its always retrorsely aculeolate leaf margins, and its mostly rough stems.
These differential characters make Galium trifloriforme a link between members of G. sect. Hylaea, with smooth stems and antrorsely directed microhairs on leaf margins, and of the G. asperifolium group of G. sect. Trachygalium, mostly with retrorsely aculeolate stems and retrorse microhairs on leaf margins (but often also with antrorse microhairs on the adaxial leaf surface). From the available material, it appears that G. trifloriforme applies to the central part of this practically continuous morphological series. This series begins with G. odoratum, G. hoffmeisteri, G. echinocarpum, G. nipponicum, and typical G. triflorum on the side of G. sect. Hylaea, continues via G. triflorum var. asprelliforme Fernald and G. trifloriforme, and ends on the other side with G. asprellum, G. dahuricum, G. blinii, and other typical members of the G. asperifolium group of G. sect. Trachygalium. It is remarkable that this transitional series apparently corresponds to a polyploid complex with marginal taxa including 2x-, G. triflorum 4x- and 6x-, and G. trifloriforme ± 10x-cytotypes. Thus, phylogenetic reticulation may have caused the still insufficiently resolved taxonomic confusion around G. triflorum, G. trifloriforme, and their relatives (cf. Pobedimova et al., loc. cit.: 287-381; Cufodontis, loc. cit.; Yamazaki, loc. cit.; Ehrendorfer et al., Fl. Iranica 176: 182. 2005).
Among the relatively few relevant PE, KUN, and WU specimens we have seen from China and the Himalaya only two typical Galium triflorum specimens with antrorsely aculeolate leaf margins were found (see there); otherwise, only plants corresponding to the above description of G. trifloriforme with leaf margins retrorsely aculeolate were seen. This finding is in conflict with W. C. Chen (loc. cit.) who accepted only G. triflorum for the Chinese flora, but certainly needs verification from more extensive studies including Korea (from where G. trifloriforme was described) as well as adjacent NE Siberia and Japan, where both taxa apparently occur.