326 RANUNCULACEAE 



Achenes not smooth. 



Achenes rough-papillose, the beak straight. 17. R. parviflorus. 



Achenes muricate, the beak recurved. 18. R. arvensis. 



i. R. delphinifolius Torr. In ponds: Me. and Ont. to Mich., 

 south to N. Car., Mo. and Kan. 

 Conn. Not common but found throughout the state. 

 N. Y. Rare and local on L. I. and S. I., thence increasing but 



not very common northward. 

 N. J. Rare and local in Monmouth and Middlesex counties, 



thence increasing and not uncommon northward. 



Distribution little understood; more common northward than 

 elsewhere. 



2. R. pusillus Poir. In marshes: S. N. Y. and N. J., Pa., south 



to Fla., west to Tex. and Mo. 



N. Y. Rare and local in Westchester Co... on L. I. and on S. I. 



N. J. Rare and local in Morris and Essex Counties, increasing 

 southward but nowhere common, and not found in the pine- 

 barrens or south of them. 



Pa. Bucks and Chester counties. 



Tertiary, o: Cretaceous, common: Older Formations, decreasing 



northward. 137-220 days. Sea level-1,800 ft. 



3. R. reptans L. On shores: Newf. and Arctic Am., south to 



N. J., Penn. and Mich, and in the Rocky Mts. to Col. Also 



in Eu. and Asia. 



Conn. Near the coast in New London Co. and along the drainage 



area of the Connecticut River in Hartford Co. 

 N. Y. Reported from the north shore of L. I. near N. Y. City. 

 N. J. Mercer, Warren and Sussex counties; in the drainage area 



of the Delaware River. 

 Pa. Bucks and Northampton counties near the Delaware. 



A rare and local species, the distribution of which is little known. 



4. R. obtusiusculus Raf. In marshes: Me. and Ont. to Ga., 



west to Minn, and Mo. 



Throughout the range, except in the pine-barrens, there wanting; 

 apparently rare on L. I. and S. I. 



5. R. abortivus L. In moist ground, most common in woods: 



Newf., Lab. and N. S. to Manitoba, Fla., Ark. and Col. 



Common throughout the range, except in the pine-barrens, there 

 wanting; doubtfully north of the moraine on L. I. 



