90 RANUNCULACEAE 



Leaves palmately divided. XI. Acres. 



Beak long. XII. HiSPiDi. 



Immersed aquatics or creeping mud plants, with palmately lobed, divided, 

 or dissected leaves. XIII. Multifidi. 



Achenes prickly; annuals. XIV. Muricati. 



I. Flammulae. 

 Plants rooting at the nodes. 



Stem filiform, prostrate; petals about 3 mm. long. 1. R. reptans. 



Stem not fljiform, at first ascending; petals about 5 mm. long. 2. R. unalaschensis. 

 Plants erect or ascending, not rooting at the nodes. 



Leaves appressed-pubescent on the lower side. 3. R. microlonchus. 



Leaves glabrous. 



Blades of the basal leaves acute at the base. 



Petals spatulate or oblong, usually 6-8, 6-8 mm. long. 4. R. alismaefolius. 

 Petals obovate, usually only 5. 



Petals 7-10 mm. long; plants over 2 dm. high; leaves not very thin. 



5. R. Bolanderi. 

 Petals 5-6 mm. long; plant low, seldom 2 dm. high; leaves very tliin. 



6. R. alismcUus. 

 Blades of the basal leaves cordate or at least rounded at the base. 



7. R. Populago. 



II. NiVALES. 



Leaf-blades spatulate or elliptic, 2-4-toothed at the apex. 8. R. hfacauleyi. 



Leaf-blades of the basal leaves reniform or flabelliform, 3-5-lobed or 3-5-cleft. 



9. R. nivalis. 



III. Glaberrimi. 

 One species. 10. R. glaberrimus. 



IV. Affines. 



Achenes pubescent, with a short recurved beak; heads oblong to cylindric. 



Some of the basal leaf-blades merely crenate, the rest mostly 3-cleft at the apex, with 

 a narrow middle lobe. 

 Sepals densely villous. 



Petals broadly obovate, about 1 cm. long. 11. R. cardiophyllus. 



Petals wanting. 29. R. apetalus. 



Sepals not densely villous; petals oblong-obovate, 3-6 mm. long. 



Petals 5-6 mm. long; heads of achenes oblong. 12. R. inamoenus. 



Petals 3-5 mm. long; heads of achenes cylindric. 13. R. micropetalus. 



Basal leaf-blades digitately or pedately cleft with acute lobes. 



Basal leaf-blades reniform or rounded-cordate. 14. R. affinis. 



Basal leaf-blades cimeate-flabclliform. 15. R. saxicola. 



Achenes glabrous; beak straight, usually slender. 



Plant glabrous, except the more or less villous sepals. 



Petals 7-12 mm. long; lobes of the basal leaves acutish. 



Basal leaf-blades cuneate-flabelliform; head of achenes somewhat oblong, 

 5-10 mm. long. 

 Basal leaf-blades cleft half way down or less. 15. R. saxicola. 



Basal leaf-blades cleft more than half way down. 16. R. eziynius. 

 Basal leaf-blades reniform or at least truncate at the base, divided more than 

 half way down; heads of achenes globular. 17. R. Suksdorfii. 



Petals 4-8 mm. long; lobes of the basal leaves obtuse or rounded. 



Heads of fruit decidedly oblong; basal leaf-blades orbicular, seldom reniform, 

 the earliest not cleft more than half way down. 

 Leaves thick; petals about 4 nim. long. 18. R. utahensis. 



Leaves thin; petals about 6 mm. long. 19. R. alpeophilus. 



Heads of achenes spherical or nearly so; basal leaf-blades decidedly reniform, 

 cleft deeper than half way down. 

 Lobes of the upper stem-leaves elliptical, oval or obovate. 



20. R. Eschscholtzii. 

 Lobes of the upper stem-leaves linear to oblong. 



Stem about 2 dm. liigh; lateral lobes of the basal leaves 2-3-toothed. 



21. R. Helleri. 



Stem less than 1 dm. high; lateral lobes of the basal leaves 4-5-toothed. 



22. R. vericundus. 

 Plant more or less pubescent. 23. R. ovalis. 



V. Digitati. 



One species. 24. R. Joris. 



VI. Triternati. 



Plant less than 1 dm. high; petals about 5 mm. long; segments of the leaves very short, 



3-5 mm. long; beak recurved. 25. R. Drunimondii. 



Plant usually more than 1 dm. high; petals 5-18 mm. long; segments of the leaves 1 cm. 

 or more long; beak slender, not recurved. 

 Primary divisions of the basal leaves petiolate; segments linear, somewhat narrowed 



downward; stems usually several-flowered; roots fibrous. 26. R. slenolobus. 

 Primary divisions of the basal leaves sessile; segments narrowly linear, almost fili- 

 form, not narrowed downward; stems 1-2-flowered; roots fleshy-fibrous. 



27. R. adoneus. 



VII. Pygmaei. 



Sepals glabrous or nearly so; lateral lobes of the basal leaves 2-3-tootlied. 



28. R. pygmaeiis. 



