Tetrastigma yunnanense var. triphyllum

Kochaiphat, Phongsakorn, Trias-Blasi, Anna & Pornpongrungrueng, Pimwadee, 2014, A new combination and new records of Tetrastigma (Vitaceae) from Thailand, Phytotaxa 183 (4), pp. 272-278 : 277

var. triphyllum ( Fig. 1C, D )

Sub-woody climber. Stems terete, mature stems flaky; tendrils palmately 5–7 branched; stipules 2, ovate-deltoid, 0.3–0.6 × 0.3–0.5 cm, glabrous. Leaves compound, palmately 3-foliolate; petiole 2.5–8.0 cm long, pilose; leaflets papyraceous; terminal leaflet petiolule 0.1–0.3 cm long, pilose, terminal leaflet blade rhombic-broadly lanceolate, 2.8– 9.0 × 1.0– 4.5 cm, base cuneate-obtuse, margin broadly serrate with teeth at apex, apex acute-attenuate, lateral leaflet petiolule, 0.05–0.2 cm long, pilose, lateral leaflet blade ovate-lanceolate, 1.5–6.5 × 0.8–3.8 cm, base asymmetricalround or asymmetrical-cuneate, margin as terminal leaflet, apex acute; veins conspicuous on both sides, 1 main basal vein, 5–8 pairs of lateral veins. Inflorescences in female plants on pseudo-terminal branch, compound umbel, globose, 2–2.5 cm in diameter; peduncles 1–1.2 cm long, pilose, male plants not seen. Male flowers not seen. Female flowers bud 0.2–0.25 cm long, pedicels 0.2–0.35 cm long, slightly pilose; calyx disciform, lobe-inconspicuous, glabrous, margin entire; corolla squarrose at anthesis, petals ovate, 0.2–0.3 × 0.1–0.2 cm, apex rounded, outer surface glabrous; disc membranaceous, adnate to the lower part of ovary; staminode filiform, 0.6–0.8 mm long; ovary ovoid, 1.8–2.0 × 1.7–2.0 mm; style truncate, ca. 0.5 mm long; stigma 4-lobed, callose. Berries and Seeds not seen.

Distribution:— China and Thailand.

Distribution in Thailand:—NORTHERN: Nan ( Fig. 2 ).

Ecology:—Limestone mountains, in upper montane scrub forest, at 1750 m elev.

Phenology:—Flowering in February.

Specimens examined:— Thailand. Nan: Doi Phu Wae, P. Srisanga, S. Sasirat, W. Pongamornkul, S. Sukiam & P. Panyachan 2422 ♀ fl. ( QBG, Herbarium of Biology Department , Chiang Mai University) .

Conservation status in Thailand:— A single population of this species has been recorded, and is represented by only one specimen collected in Doi Phu Wae, Doi Phu Kha National Park (Nan). This species has an extremely restricted distribution with a very specific habitat (upper montane scrub forest on limestone soil), therefore a preliminary assessment of endangered ( EN) is indicated .

Note:—This species is distinguished by its palmate tendrils and 3-foliolate leaves. It is the only species from Thailand with palmate tendrils. This variety differs from Yunnan ( China) endemic var. hirtum (Gagnep.) W.T. Wang (1979: 84) , by its densely pilose young branches, leaves, petioles and pedicels.

Figures

FIGURE 1. A. T. assimile, B. T. macrocorymbum, and C–D. T. triphyllum var. triphyllum. (A. photo by Phongsak Phonsena)

FIGURE 2. Distribution map of T. assimile (), T. macrocorymbum (), T. pyriforme (') and T. triphyllum var. triphyllum () in Thailand.