Genus 20. 



CROWFOOT FAMILY. 



105 



I. Ranunculus delphinifolius Torr. Yellow Water-Crowfoot. Fig. 1895. 



Raiuiiicnlus muttifidus Pursh, FI. Am. Sept. yif). 1814. 



Not Forsk. 1-75. 

 R. delfhinifoliiis Torr. ; Eaton, Man. Ed. 2, 395. iSiS. 

 Ranunculus lacustris Beck & Tracy, N. Y. Med. and 



Phys. Journ. 2: 112. 1823. 

 R, niissouricnsis Greene, Erythea 3: 20. 1895. 



Aquatic or partly emersed, branching, sometimes 

 several feet long. Immersed leaves repeatedly di- 

 vided into capillary segments, short-petioled, i'-3' 

 long; emersed leaves glabrous or pubescent, V-2' 

 broad, petioled or the upper nearly sessile, 3-S-di- 

 vided, the divisions cleft into linear or cuneate 

 segments ; flowers yellow, 3"-i8" broad ; petals 5-8, 

 much longer than the sepals ; head of fruit globose, 

 or oblong, 3"-5" long ; achenes less than l" long, 

 callous-margined, at least toward the base, tipped 

 with a straight persistent beak of one-half their 

 length or more. 



In ponds, Maine and Ontario to Michigan, Oregon, 

 North Carolina, Missouri and Arkansas. The so-called 

 var. terrestiis is an emersed form. June-Aug. 



2. Ranunculus Purshii Richards. Pursh's Buttercup. Fig. 1896. 



Ranunculus Purshii Richards. Frank. Journ. 741. 1823. 

 Ranunculus limosus Nutt. ; T. & G. Fl. N. A. i : 20. 1S38. 

 Ranunculus muttifidus var. repcns S. Wats. Bot. King's 

 Exp. 8. 1871. 



Perennial, floating or creeping, usually pubescent 

 at least on the younger parts, sometimes densely so; 

 stems slender, often rooting from the lower nodes, 

 2'-8' long. Leaves slender-petioled, orbicular or 

 reniform in outline, i'-l' wide, palmately divided 

 nearly to the base into obtuse lobes or segments ; 

 flowers yellow, long-peduncled, 2"-y" broad ; sepals 

 spreading, ovate, obtusish, early deciduous; petals 

 about 5 ; head of fruit subglobose or ovoid-oblong, 

 obtuse, 2"-T," long; achenes little compressed, 

 smooth, not margined, ' long, acutish on the back, 

 abruptly tipped with a slender style of about one- 

 third their length. 



In moist soil. Nova Scotia to Alaska, Michigan, North 

 Dakota, south in the Rocky Mountains to New Mexico 

 and Utah. July-Aug. 



3. Ranunculus- hyperboreus Rottb. Arctic Buttercup. Fig. 1897. 



Ranunculus hyperboreus Rottb. Skrift. Kjoeb. Selsk. 10: 458. 1770. 



Stem slender, glabrous, filiform, creeping, 2'-6' long. Leaves 

 petioled, 3-lobed or cleft, broadly ovate, 2"-$" broad, 2"-^," 

 long, obtuse, the base cuneate or rounded, the lobes oblong, ob- 

 tuse, the lateral ones sometimes toothed ; petioles sheathing and 

 biauriculate ; flow-ers few, 2"-2," broad, yellow ; petals slightly 

 shorter than the reflexed sepals ; peduncles 4"-6" long ; head of 

 fruit globose. 2" broad ; achenes slightly compressed, with a 

 minute blunt point. 



Labrador. Greenland, arctic America, Iceland, northern Europe and 

 Siberia. Summer. 



