Thalictrum

Li, Jin-Yu, Xie, Lei & Li, Liang-Qian, 2015, A new species of Thalictrum (Ranunculaceae) from southern Tibet (Xizang), China, Phytotaxa 207 (3), pp. 281-285 : 284-285

Key to the species of Thalictrum from central Himalayas

1. Flowers solitary, axillary (small herb with tiny leaflets) ........................................................................................... Th. squamiferum

- Flower in few- to many-flowered, terminal inflorescences................................................................................................................2

2. Leaves all basal; inflorescence raceme-like ..................................................................................................................... Th. alpinum

- Cauline leaves present; inflorescence cymose...................................................................................................................................3

3. Cauline leaves ternate, basal leaves absent ..................................................................................................................... Th. virgatum

- Cauline leaves 2–4-pinnately compound............................................................................................................................................4

4. Sepals large and showy, more than 5 mm long, pink to purple..........................................................................................................5

4. Sepals usually not conspicuous, less than 5 mm long, deciduous, whitish yellow, green, or sometimes pink..................................6

5. Leaves, stems, inflorescences, and carpels hairy, (leaf 1–2 cm long), without axillary bulbils..................................... Th. reniforme

- Plant glabrous, with axillary bulbils in upper leaves..................................................................................................... Th. chelidonii

6. Styles curved, beak of achene hooked at tip.......................................................................................................................................7

- Styles straight, beak long or short, not hooked at tip.......................................................................................................................10

7. Carpels usually more than 25, beaks long, straight, hooked at tip, plants 18–30 cm tall........................................ Th. saniculiforme

- Carples usually less than 25, plants more than 40 cm tall..................................................................................................................8

8. Achene flat, laterally compressed.......................................................................................................................................................9

- Achene body ovate, not compressed ............................................................................................................................. Th. javanicum

9. Inflorescence monochasium elongate, raceme-like densely flowered, achenes ovate...................................................... Th. atriplex

- Inflorescence few flowered, achenes obliquely narrowly ovoid or cylindric ............................................................. Th. rostellatum

10. Plant all glabrous..............................................................................................................................................................................11

- Plant hairy at least on leaves............................................................................................................................................................13 11. Stigma winged; achenes sessile; leaflet more than 1 cm long....................................................................................... Th. foliolosum

- Stigma not winged; achenes stalked, leaflet less than 8 mm long....................................................................................................12

12. Inflorescence a raceme-like pleiochasium; achenes reflexed........................................................................................ Th. rutifolium

- Inflorescence an elongated panicle; achenes winged, erect .............................................................................................. Th. elegans

13. Anthers blunt, without a beak or mucro at apex........................................................................................................ Th. platycarpum

- Anthers beaked, apiculate or muronate............................................................................................................................................14

14. Stems glandular-pubescent, stigma significantly winged................................................................................................ Th. foetidum

- Stems not glandular-pubescent, stigma not or slightly winged........................................................................................................15

15. Leaflets large, usually 3–5 cm long, filaments purple, sepals white or pink........................................................ Th. austrotibeticum

- Leaflets small, less than 2 cm long, filaments white, sepals yellowish green..................................................................................16

16. Stigma not winged; achenes with short hairs; leaflets not glaucous .................................................................................... Th. finetii

- Stigma slightly winged; achenes glabrous; leaflets glaucous......................................................................................... Th. cultratum