EANUNCULACEAE 93 



Leaves all 3-parted. 4. S. sceleraius. 

 Plants pubescent. 



Beak of achene strongly recurved. 5. B. recurvaius. 



Beak of achene minute. 3. R. mieranihus. 

 Petals twice the length of the calyx. 



Plants erect. 6. B. acris. 

 Plants spreading. 



Stems pubescent or glabrous. 7. B. sppientrionalis. 



Stems densely villous. 8. B. hiapidus. 



1. R. delphinifolius Torr. Yellow Watek-ckowfoot. Stems float- 

 ing or creeping in the mud : leaves dissected into capillary segments or 

 palmately 3 divided, the segments incised and lobed : flowers S^-ia" 

 broad : achenes callous-margined. — In Fish Lake and near Little Blue 

 Tank. May-June. 



2. R. abortivus L. 6''-20'' high, glabrous : early basal leaves cordate, 

 crenate : the oanline leaves nearly sessile, parted and lobed : flowers 'if'-Z" 

 broad : fruiting head globose : achenes minutely pointed. — Common in 

 moist grounds. April-May. 



3. R. micranthus Nutt. e'-lS' high, pubescent : roots tuberous- 

 thickened : basal leaves 3-parted or divided. Otherwise like the last. — 

 Frequent in woods throughout. April-May. 



4. R. sceleiatus L. 6''-24' high, stout : basal leaves 3-5-lobed, the 

 lobes often toothed : flowers 3"-4'''' broad : fruiting head oblong-cylin- 

 dric, V-W long : achenes minutely pointed.-^-On muddy sand-bars along 

 the Missouri River. Sometimes frequent. May-November. 



5. R. recurvatus Poir. l°-2° high, hirsute : leaves all 3-divided, the 

 lobes cut and toothed : flowers 4"-5" broad : fruiting head globose : 

 achenes with a long recurved beak. — Frequent in moist woods through- 

 out. May-July. 



6. R. acris L. 2°-3° high, erect, hairy : leaves 3-divlded. their 

 sessile divisions again cleft and parted : flowers V broad : achenes short- 

 beaked. — Earely adventized along the railroad at ShefSeld and Courtney. 

 May-June. 



7. R. septentrionalis Foir. Stems ascending or procumbent and 

 widely spreading, sparingly pubescent or glabrate : leaves 3-divided, 

 their divisions stalked, and again 3-parted, the lobes incised : flowers V 

 broad : achenes long-tipped. — Common in low woods, especially in the 

 northern part. April-May. 



8. R. biapidus Michx. Like the last but more erect and densely 

 villous : achenes more slender-tipped. — On low prairies near Buckner. 

 Rare. May-June. 



10. BATRACHIUM S. F. Gray. 



Aquatics with dissected leaves and white flowers. Like BanuneuXm 

 but achenes transversely wrinkled. 



1. B. divaricatum (Schrank.) Wimm. White Watbk-ceowfoot. 

 Leaves V long, much divided, rigid when drawn out of water : flowers 



