Tetrastigma

Kochaiphat, Phongsakorn, Trias-Blasi, Anna & Pornpongrungrueng, Pimwadee, 2016, Two new species of Tetrastigma (Miq.) Planch. (Vitaceae) from Thailand, European Journal of Taxonomy 201, pp. 1-12 : 2-4

Key to the species of Tetrastigma in Thailand

1. Tendrils5–7palmately branched;leaves palmately3-foliolate........ T. triphyllum (Gagnep.)W.T.Wang

– Tendrils simple or bifurcate; leaves simple, palmately 3–5(–7)-foliolate or pedately 5–7(–9)-foliolate ........................................................................................................................................................... 2

2. Inflorescences on old stems (cauliflorous plants), more than 5 inflorescences per nodes ..................... ............................................................................................................................. T. cauliflorum Merr.

– Inflorescences on young branches, 1–3 inflorescences per nodes ...................................................... 3

3. Young branches with 4–5 sharp ridges ........................................ T. quadrangulum Gagnep. & Craib – Young branches round or nearly round .............................................................................................. 4

4. Leaves palmately 3–5(–7)-foliolate or mixed with simple leaves or all leaves simple ..................... 5 – Leaves pedately 5–7(–9)-foliolate rarely mixed with 3-foliolate ..................................................... 16

5. Stems verrucose or with corky protuberances ................................................................................... 6 – Stems smooth, pubescent or with flaky cork ...................................................................................... 8

6. Stems with corky protuberances; leaves ovate to elliptic; stigma distinctly 4-lobed ......................... 7 – Stems verrucose; leaves lanceolate; stigma peltate ............................................. T. harmandii Planch.

7. Leaves fleshly; stigma cruciform; berries ellipsoid when dry ............... T. cruciatum Craib & Gagnep. – Leaves coriaceous or papyraceous; stigma pointed lobes; berries pyriform when dry ......................... ......................................................................... T. assimile (Kurz) C.L.Li ex Kochaiph. & Trias-Blasi

8. Shrubs, creeping, erect or decumbent ................................................................................................ 9 – Lianas .............................................................................................................................................. 10

9. Leaves simple or mixed with palmately 3(–5)-foliolate; pedicel 0.4–0.6 cm long ............................... ....................................................................................................................... T. bambusetorum Craib – Leaves palmately 3-foliolate; pedicel 0.8–1.2 cm long .................................... T. apiculatum Gagnep.

10. Leaflets glabrous .............................................................................................................................. 11 – Leaflets pubescent or hirsute at least along the midrib on lower leaf surface ................................... 15

11. Female flower disc conspicuous, thick and adnate to lower part of ovary ........................................ 12 – Female flower disc inconspicuous ................................................................................................... 14

12. Terminal leaflets broadly elliptic to rhombic; berries pyriform when dry ............................................. .................................................................................. T. pedunculare (Wall. ex M.A.Lawson) Planch. – Terminal leaflets elliptic, ovate or lanceolate; berries ellipsoid when dry ........................................ 13

13. Leaves coriaceous or subcoriaceous .................................................................. T. erubescens Planch. – Leaves papyraceous ........................................................................ T. dubium (M.A.Lawson) Planch.

14. Leaflets broadly ovate or broadly elliptic, apex caudate ................. T. campylocarpum (Kurz) Planch. – Leaflets lanceolate, apex attenuate ..................................................... T. planicaule (Hook.f.) Gagnep.

15. Ovary brownish hirsute; leaves palmately 5-foliolate ................ T. obovatum (M.A.Lawson) Gagnep. – Ovary glabrous; leaves palmately 3-foliolate ................................. T. dubium (M.A.Lawson) Planch.

16. Leaves 5-foliolate, rarely mixed with 7-foliolate ............................................................................. 17 – Leaves 7(–9)-foliolate, rarely mixed with 5-foliolate ...................................................................... 29

17. Branches glabrous; leaflets glabrous on both surfaces ..................................................................... 18 – Branches more or less pubescent; leaflets pubescent at least along the midvein on lower leaf surface ......................................................................................................................................................... 26

18. Secondary branches of peduncle 2 ....................................................................... T. baenzigeri C.L.Li – Secondary branches of peduncle more than 2 .................................................................................. 19

19. Berries pyriform or triangular when dry .......................................................................................... 20 – Berries globose, ovoid or ellipsoid when dry ................................................................................... 21

20. Terminal leaflets ovate–lanceolate, 3–4 × 6–9 cm; berries pyriform when dry ... T. pyriforme Gagnep. – Terminal leaflets obovate or elliptic, 4–5.5 × 9–12 cm; berries triangular when dry ............................ .......................................................................................... T. rumicispermum (M.A.Lawson) Planch.

21. Inflorescences compound umbel on pseudo-terminal branch or axile, umbelliform, loose; tendrils bifurcate ............................................................................................... T. serrulatum (Roxb.) Planch. – Inflorescences compound umbel on axile, globose, compact; tendrils unbranched ......................... 22

22. Female flower disc inconspicuous .................................................... T. pachyphyllum (Hemsl.) Chun – Female flower disc conspicuous, thick and adnate to lower part of ovary ........................................ 23

23. Stigma peltate, rounded or slightly 4-lobed ..................................................................................... 24 – Stigma cruciform, 4-lobed, obtuse, acute or pointed apex ............................................................... 25

24. Berries 1.8–3.0 × 1.5–2.5 cm; seed oblongoid; female flower disc 4-angled ........................................ .................................................................. T. jaichagunii C.L.Li ex Kochaiph. & Trias-Blasi sp. nov. – Berries 0.8–1.2 × 0.8–1.2 cm; seed ellipsoid; female flower disc rounded ......... T. harmandii Planch.

25. Stigmas 4 acute or pointed lobes, style tubular 0.5–0.8 mm long ... T. dubium (M.A.Lawson) Planch. – Stigmas 4 obtuse lobes, style absent ............................. T. calcicola Kochaiph. & Trias-Blasi sp. nov.

26. Leaflets broadly elliptic or ovate ..................................................................................................... 27 – Leaflets narrowly elliptic or lanceolate ........................................... T. dubium (M.A.Lawson) Planch.

27. Leaflets pubescent along nerve or at least along the midrib on the lower surface ............................ 28 – Leaflets pubescent on both surfaces ........................................ T. macrocorymbum Gagnep. ex J.Wen

28. Berries up to 1.5 cm in diameter .............................................................................. T. pilosum C.L.Li – Berries more than 2 cm in diameter ....................................................... T. siamense Gagnep. & Craib

29. Berries 2–2.5 cm in diameter ................................................................................ T. teaniatum C.L.Li – Berries 0.8–1.5 cm in diameter ........................................................................................................ 30

30. Outer petals densely papillose ..................................... T. leucostaphylum (Dennst.) Alston ex Mabb. – Outer petals glabrous ....................................................................................................................... 31

31. Secondary vein almost 90° with midrib; old branches verrucose, light brown; stigma 4 pointed lobes .............................................................................................................................. T. delavayi Gagnep.

– Secondary vein angle nearly 45° with midrib; old branches flaky, grey; stigma 4 rounded lobes or nearly globose, not lobed ............................................................................. T. godefroyanum Planch .