RANUNCULACEAE (BUTTERCUP FAMILY) 199 



Flowers large (petals 5-8 mm. long); stamens many. 



Leaves short and scarcely collapsing when withdrawn from the 



water . . . . . . . . . . 2. B. trichophyllum. 



Leaves longer and collapsing when withdrawn from the water . 3. B. flaccidum. 

 Flowers smaller; stamens 5-12 . . . . . . . 4. B. confervoides. 



1. Batrachium longirostre (Godr.) F. Schutz. Arch. Fl. Fr. et Allem. 1: 70. 

 1844. Stem leafy (the internodes short): leaves nearly sessile, all submersed; 

 segments numerous, filiform, 12-15 mm. long, hardly collapsing when with- 

 drawn from the water; the stipules broad and hairy: peduncles moderately 

 stout, 2-3 cm. long: petals ovate, 5-7 mm. long: achenes in a globose head, 

 distinctly beaked. Ponds and streams; infrequent in our range, but common 

 eastward. 



2. Batrachium trichophyllum (Chaix) Bossch. Prod. Fl. Bat. 5. 1850. 

 Wholly submersed; the stems long (3 dm. or more), with rather long inter- 

 nodes: leaves petioled; their segments short (10-16 mm.), scarcely collapsing 

 when withdrawn from the water; stipules broad, short, hairy: flowers rather 

 large, on stoutish peduncles bringing them just above the surface: achenes 

 apiculate but not beaked, on a hairy receptacle. Ponds and streams, fre- 

 quent; across the continent and in Europe. 



3. Batrachium flaccidum (Pers.) Rupe. Fl. Cauc. 15. 1869. Scarcely dif- 

 fering from the preceding except in the shorter internodes, more numerous 

 longer-petioled leaves, which have longer more slender segments that collapse 

 on being withdrawn from the water. Occurring not only in N. America but 

 in Europe and Asia. 



4. Batrachium confervoides Fries, Bot. Notiser 121. 1844. Differing from 

 the three preceding in the filiform stem, the very flaccid leaves, the smaller 

 flowers, the few stamens, and the conic (not ovoid) receptacles. In cold wa- 

 ters; northern Wyoming to Alaska and Lake Winnipeg. 



12. RANUNCULUS L. BUTTERCUP. CROWFOOT 



Mostly low perennial herbs, more rarely annual, with leaves varying from 

 entire to divided, parted or dissected; those of the stem alternate. Flowers 

 solitary or several in a subcorymbose cluster. Sepals usually 5. Petals 3-15, 

 with a little scale-covered pit at the base inside, yellow (in some degree), 

 often broad and conspicuous. Achenes aggregated in a globular or oblong 

 head, usually compressed; the style often in part (more rarely as a whole) 

 persisting and pointing the achene. 



AMPHIBIOUS AQUATICS, the submersed leaves, if any, 



capillary-mult ifid. 

 Leaves orbicular in outline, multifid or many-toothed or lobed 1. R. Purshii. 



Leaves reniform, 3-lobed 

 MARSH PLANTS, perennial 

 TERRESTRIAL PERENNL 



All the leaves entire 

 Some of the leaves entire 



by creeping stolons 

 ALS, often growing in wet places. 



2. R. natans. 



3. R. reptans. 



4. R. calthaeflorus. 



5. R. glaberrimus. 



None of the leaves entire. 



Some or all of the radical merely crenate-dentate, not divided 



or parted. 

 Achenes glabrous, in a globose head. 



Sepals densely villous with brown hair . . . 6. R. Macauleyi. 



Sepals glabrate or ciliate-pubescent. 



Radical leaves reniform-cordate . . . . 7. R. abortivus. 



Radical leaves ovate or suborbicular . . . 8. R. ovalis. 



Achenes pubescent, in an oblong head. 



Petals small, spatulate-oblong . ..... 9. R. inamoenus. 



Petals large, obovate-suborbicular ..... 10. R. cardiophyllus. 



Most of the radical cleft to the middle or below. 

 Head of carpels elliptic or oblong. 



Achenes pubescent . . . . . . . . 11. R. pedatifidus. 



Achenes glabrous 12. R. alpeophilus. 



Head of achenes globose . . . . . . . 13. R. pygmaeus. 



All of the leaves deeply cleft or parted. 



Plants of alpine or subalpine stations, 3-14 cm. high. 

 Flowers small. 



Sepals glabrous ........ 14. R. Jovis. 



Sepals villous . . . . . . . . 15. R. Grayi. 



