EANUNCULUS 13 



opposed to non- contiguous petals, and the peduncles not tapering 

 instead of tapering, appear to be by no means constant. Babington's 

 R. floribundus is not uncommon in Windsor Great Park and in many 

 other localities. The variety or form truncatus ^Batrachium inmcatum, 

 Dumort. in Bull. Soc. Bot. Belg. ii. 215) has the outer base of the 

 lateral segments of the leaves much rounded. This is a common form. 

 The variety which occurs in more swiftly running streams with very 

 much longer flower-stalks and a more draM^n-out habit is probably 

 R. elongatus, F. Schultz, in Billot, i. 113. 



The plant from Wigmoreash Pond has short, rather rigid leaf-seg- 

 ments, and is the var. rigidum. See H. Beaudouin, in Exc. Soc. Dcmph. 

 2nd series, n. 7. 



The mud form, R. aquatilis var. succidentus of Koch's Syn. Fl. Germ. 

 ii. 1837), II, is also frequent, and sometimes, though rarely, has hetero- 

 phyllous leaves. 



R. peliatus, Schrank, is given, with a mark of doubt, by Syme as 

 a synonym of R. heterophijUus. To me the differences which separate 

 the two plants v/ould be best expressed by making one a variety of the 

 other. 



R. peltatus, in one or other of its forms, is undoubtedly our com- 

 monest and most widely distributed Water Buttercup. Some of our 

 quiet pools on the river are white with its blossom, and the same may 

 be said of many of the ponds in the central part of the county. Its 

 long trailing stems and masses of submerged leaves are conspicuous 

 features in the Kennet, Lambourn, and other swiftly flowing streams. 

 The plant is found in all the bordering counties. 



By many authors this is taken as the type of R. aquatilis, Linn. 



E. fluitans, Lam. Fl. Fr. iii. 184 (1778), Water Buttercup. 



R. fluvialilis, [Web. ex] Wigg. Prim. Fl. Holsat, 42. Batracliium 



fluitans, Wimm. Fl. Schles. 9 (1841). B. fluviatile, S. F. Gray, Nat. 

 Arr. ii. 722 (1821). 



Top. Bot. 9. Syme,E. B. i. 17, t. 16. Nyman, 15. Fl. Oxf. 9. 



Native. Lacustral. Rivers and swift streams. Locally abundant. 

 P. June-August. 



First record. Ranunculus sive Polyanthemo aquatili alba affine Millefolium 

 Mar airiphyUum fluitans. J. B. River Ouse [Isis] about Oxford, plen- 

 tifully, Ray's Catalogus, 260, 1670. The record is repeated on 

 p. 250 in ed. 2 of the same work, 1677. R. fol. capillaceus circum- 

 scriptions oblonga, about Oxford, Sir Joseph Banks, 1770, in Herb. 

 Brit. Mus. 



1. Isis. In the Cole and the Upper Thames from Lechlade to Oxford. 



2. Ock. Near Radley, Boswel. Plentiful in the Thames from 



Oxford to Sutton Courtney. In the Ock near Marcham. 



