424 FLORA 



tttt Terrestrial species with some or all the leaves lobed or divided. 

 Calyx conspicuously black-pubescent ; arctic; flowers white or light yellow. 



10. K. nivalis. 

 Calyx glabrous or pubescent ; flowers yellow. 



1. Achenes smooth, neither papillose, muricate nor spiny. 



Plants low, arctic-alpine ; leaves small, palmately lobed. 



Flowers 4-6 mm. in diameter ; sepals glabrous or slightly hairy. 



11. R. pygmaeus. 

 Flowers about i cm. in diameter; sepals densely hairy. 



12. R. Sabini. 

 Plants neither arctic nor alpine. 



Basal leaves, some or all of them, merely crenate. 

 Head of fruit oblong, 2-3 times as long as thick. 



Flowers 4-12 mm. in diameter ; sepals glabrate or slightly hairy. 



13. R. pedatifidus. 

 Flowers 1.5-2 cm. in diameter; sepals densely villous. 



14. R. cardiophyllus. 

 Head of fruit globose or subglobose. 



Petals large, oblong, longer than the sepals. 



Basal leaves oval or ovate, not cordate. 15. R. ovalis. 

 Basal leaves reniform or orbicular, cordate. 



16. R. Plarveyi, 

 Petals small, oblong, shorter than or equalling the sepals. 



Styles very short, curved. 



Basal leaves cordate ; plant glabrous or nearly so. 



17. R. abort 't'vus. 

 Basal leaves not cordate ; plant villous. 



18. R. micranthns. 

 Styles subulate, hooked, nearly one-half as long as the achene. 



19. R. Alleghaniensis. 

 Leaves all lobed or divided. 



Plant glabrous ; stem hollow ; flowers very small. 20. R. sceleratus. 

 Plants more or less pubescent. 



Beak of the achene strongly hooked ; flowers 8-10 mm. wide. 



21. R. recurvatus. 

 Beak of the achene short. 



Erect plants, naturalized in fields ; flowers 25 mm. broad. 

 Calyx spreading ; roots fibrous. 22. R. acris. 

 Calyx reflexed ; stem bulbous-thickened at base. 



23. R. bulbosus. 



Erect or ascending plants of moist soil ; flowers 6-12 mm. 

 broad. 



Petals not longer than the reflexed sepals ; head of fruit 

 oblong to cylindric. 24. R. Pennsylvanicus. 



Petals longer than the sepels ; head of fruit spherical- 

 ovoid. 25. R, Maconnii. 

 Ascending and creeping by stolons; flowers 2.5 cm. broad. 



26. R. repens. 



Beak of the achene longs stout or slender ; flowers 12-36 mm. 

 broad. 



Beak stout, sword-shaped ; roots slender ; leaflets cuneate at 

 base. 27. R. septentrionalis. 



Beak of achene slender, subulate ; roots thickened. 

 Leaf-segments broad, oblong or obovate. 



28. R. hispidus. 

 Leaf-segments narrow, linear-oblong. 



29. R.fascicularis. 



2. Achenes with a few scattered papillae near the margins. 30. R. parvulus. 



3. Achenes rough-papillosed all over. 31. /t*. parviflorus. 



4. Achenes muricate or spiny. 



Leaf-lobes broad, obtuse. 32. R. muricatus. 



Leaf-lobes narrow, subacute. 33. R. arvensts. 



i. Ranunculus Purshii Richards. PURSH'S BUTTERCUP. (I. F. f. 1596.) 

 Aquatic or creeping, pubescent at least on the younger parts. Leaves slender- 

 petioled, 6-24 mm. wiJe. palmately divided nearly to the base into obtuse lobes 

 or segments; petals about 5; head of fruit subglobose or ovoid oblong, 4-6 mm. 

 long, In moist soil, N. S. to .Mich., Minn., western Ont. and Arctic Am., west to 

 Br. Col., Colo, and Utah. July-Aug. 



