FLORA OF OXFORDSHIRE. 283 
Syme. In 1885 I noticed the floating form in a small pond near 
the brickyards, which now probably occupy the old station, and 
a month later these being dried up the plant assumed the heath form. 
7. Thames. Binfield Heath, very rare, see Rep. of Rec. Club, 1883. 
Berks. South Hinksey. Northants, Gloster W., Warwick. 
P. rufescens, Schrad. 
Syme, E. B. ix. 30.1402. Nym, 681. 
Native. Slow streams and ponds. P. July. 
First record, T. Bees. and A. French, about 1860. 
8. Swere. Back brook Huscott Mill. Ditch near Grimsbury Green, 
tif in Northants. This is the P. protens var. b. heterophyllus of 
the Banbury list. 
5. Isis. Wychwood Ponds, Rev. FE. Fox. 
Berks. Hampstead Park. Bucks, Warwick. 
?P. gramineus, L. P. heterophyllus, Schreb. 
Top. Bot. 418. Bees. Cat. Syme, E. B. ix. 35. 1406. 
Native (?) River, canal. Rare, ? if ever found. 
3. Swere. [River in Mill Meadow, Bees. List], see above, Canal 
above Heyford, Rev. EH. Fox. I have not seen specimens, in 
absence of these the record must be queried, although there is no 
intrinsic reason why this plant should be absent from Oxfordshire. 
Berks. Bulmersh Lake, F. Tufnail. 
P. lucens, LZ. 
Top. Bot. 417. Syme, E. B. ix. 38. 1408. Nym. 682. 
Native. Lacustral. Rivers, canal, ponds. Common in all the dis- 
tricts. P. June, July. 
First record, Sib. 1794. 
It is an abundant plant of the Thames, and gradually merges into the 
var. P. acuminatus, Schum. Comp. Cyb. 583. 
4. Ray. Islip, Marston, the Parks. 
5. Isis. Eynsham, Chinnor, Yarnton. 
6. Thame. Dorchester, Iffley. 
In the Cherwell some plants approaching Zizii occurred with the type. 
P. decipiens, Nolte. 
Syme, E. B. ix. 39. 1409. Nym. 682. 
Native. Canal. Veryrare. P. July. 
First record, the Author, 1884. 
4, Ray. Floating specimen in Canal, Upper Heyford, not the typical 
broad leaved Continental form, but the narrow leaved plant. 
Gloster, Warwick. 
P. prelongus, Wulf. 
Top. Bot. 419. Syme, E. B. ix. 41. 1411. Oxford. Nym. 682. 
