GENUS 20. CROWFOOT FAMILY. 105 



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



Ranunculus multifidus Pursh, Fl. Am. Sept. 736. 1814. 



Not Forsk. 1775. 



R. delphinifolius Torr. ; Eaton, Man. Ed. 2, 395. 1818. 

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



Phys. Journ. 2: 112. 1823. 

 R, missouriensis 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, A '-2' 

 broad, petioled or the upper nearly sessile, 3~5-di- 

 vided, the divisions cleft into linear or cuneate 

 -cgments; 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 i" 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. terrestris 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. 1838. 

 Ranunculus multifidus var. repens 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 f -S' long. Leaves slender-petioled, orbicular or 

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

 nearly to the base into obtuse lobes or segments ; 

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

 spreading, ovate, obtusish, early deciduous ; petals 

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

 obtuse, 2"-3" 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"-s" broad, 2" -4," 

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

 tuse, the lateral ones sometimes toothed ; petioles sheathing and 

 biauriculate ; flowers few, 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. 



