Thalictrum L.

Herbs, perennial; stems branched, erect or rambling. Leaves pinnate or ternate with 3 - 7 leaflets, often repeatedly ternatisect with numerous leaflets; petioles sheathing or auricled or stipitate at base; stipels often present. Flowers small, actinomorphic, erect or pendent in diffuse racemes or panicles, rarely few-flowered, axillary, bisexual or sometimes polygamous and plant dioecious. Sepals 4 - 5, inconspicuous or petaloid, greenish or yellowish-white or purplish. Petals absent. Stamens 5 - many, conspicuous. Carpels (1-) 5 - 10; ovule 1 in each, pendulous. Achenes sessile or stalked in heads, ribbed, margined or winged; styles persistent or caducous.

Temperate and alpine regions of N. Hemisphere; ca 150 species, 21 in India.

Literature. LECOYER, J. C. (1885) Monographie du genre Thalictrum L. Bull. Soc. Bot. Belge 24: 78 - 324, tt. 2 - 5.

KEY TO THE SPECIES

1a. Leaves simple, simply ternate or 3-foliolate

2

b. Leaves biternately or pinnately compound or decompound

4

2a. Achenes sessile

4. Thalictrum dalzellii

b. Achenes stalked

3

3a. Stipules adnate to petiole

11. Thalictrum obovatum

b. Stipule free

21. Thalictrum virgatum

4a. Plants usually not more than 30 cm high

5

b. Plants more than 30 cm high

8

5a. Achenes many, more than 12; beak long, straight, hooked at tip

18. Thalictrum saniculiforme

b. Achenes few, less than 12; beak short, not hooked at tip

6

6a. Stems surrounded by scales at base; flowers 2 - 3, axillary

20. Thalictrum squamiferum

b. Stems not surrounded by scales at base; flowers many in racemes or panicles

7

7a. Stems very short, up to 10 cm long; leaves all or mostly radical; flowers in racemes; stigma not incurved

1. Thalictrum alpinum

b. Stems longer, up to 30 cm long; leaves radical and cauline; flowers in panicles; stigma incurved

5. Thalictrum elegans

8a. Anthers beaked, apiculate or mucronate

9

b. Anthers without beak or mucro at apex

16

9a. Achenes sessile

10

b. Achenes short or long-stalked

12

10a. Flowers polygamous; anthers beaked; achenes usually 2 - 5

8. Thalictrum foliolosum

b. Flowers bisexual; anthers apiculate; achenes more than 5

11

11a. Herbs glandular pubescent

7. Thallctrum foetidum

b. Herbs not glandular pubescent

10. Thalictrum minus

12a. Achenes with stalks as long as or longer than achenes

13

b. Achenes with stalks much shorter than achenes

15

13a. Leaflets 3 - 5 mm in diam.; achenes abruptly deflexed against stalk

17. Thalictrum rutifolium

b. Leaflets more than 1 cm in diam.; achenes not so deflexed

14

14a. Flowers ca 2.5 cm across, pink, lilac or purple in dense rigid panicles

2. Thalictrum chelidonii

b. Flowers less than 1.5 cm across, greenisb white, in lax weak panicles

15. Thalictrum reniforme

15a. Panicles laxly many-flowered; flowers ca 2 cm across, greenish white

3. Thalictrum cultratum

b. Panicles 1- to few-flowered at ends of branches; flowers less than 1 cm across, purpnish

19. Thalictrum secundum

16a. Achenes sessile

17

b. Achenes stalked

19

17a. Beaks of achenes long, hooked at tip

14. Thalictrum punduanum

b. Beaks of achenes short

18

18a. Achenes ca 3 mm long; veins not prominent

6. Thalictrum falconeri

b. Achenes ca 6 mm long, strongly ribbed

9. Thalictrum Javanicum

19a. Flowers greenish

13. Thalictrum platycarpum

b. Flowers white

20

20a. Leaflets membrabnous, ca 3 cm broad

12. Thalictrum pedunculatum

b. Leaflets thick, 0.6 - 1.5 cm broad

16. Thalictrum rostellatum

List of Lower Taxa