362 FLORA OF OXFORDSHIRE. 
7. Thames. Singularly absent from the heaths on the Chilterns (?). 
Berks. Powder Hill Copse, H. Bos. 1867, and Bagley, 1858. 
Northants, extinct (?). Gloster W., Warwick. 
[A. Thelypteris, Si. Wytham Woods, Morison, 1699. Windsor Park, 
Sunninghill Wells, Brit. Berks, Warwick, Northants, extinct.] 
CYSTOPTERIS. Bernh. 
* C, fragilis, Brn. Britile Bladder Fern. 
Syme, E. B, xii. ror. 1864. Nym. 867. 
Native (?). Rupestral. Walls. Very rare. June. 
First record, South Newington Church near Banbury, 1871, Rev. J. 
Whitehead in Hb. Br. Mus. and EF. B. Penfold in Jour. Bot. ix. 305. 
There is a tradition of its occurring in Wychwood Forest. 
Gloster E., Warwick. 
POLYPODIUM. L. 
P. vulgare, L. Common Polypody. 
Top. Bot. 509. Syme, E. B. xii. 38.1842, Nym. 867. 
Native. Septal, etc. Walls, banks, hedges, tree trunks, pollard 
willows, ete. Common and generally distributed. P. Aug.—Oct. 
First record, Wm. Coles, 1657. 
Adderbury Church Yard, Adam in Eden. 
This after Filix mas, and Pteris, is our commonest fern. It is still 
found in and close to Oxford, as on pollard willows, in the Parks and 
Mesopotamia. 
Gulliver included a serrate variety, P. serratum, W., which is not 
uncommon. 
P. Robertianum, Hof. Limestone Polypody. 
P. calearewm, Sm. Phegopteris calcarea, Fee. P. Dryopteris (L.), Sib. 
Top. Bot. 510. Syme, E. B. xii. 48. 1846. Nym. 868. 
Native. Rupestral. Damp rocky ground. Very rare, P. June. 
First record, Bobart, 1699, vol. iii. 580. 
5. Isis. Cornbury Quarry, Bobart; Sib. ‘ Dryopteris, 1794; H. Bos. 
1858; Prof. Lawson and Dr. Cradock, 1871; still there in 1885. 
Bucks near Wycombe, Brit., Gloster E. 
This has been sometimes erroneously recorded as Dryopteris, L. 
[P. Dryopteris, L. Oak Fern, 
Syme, E. B. xii. 46. 1845. 
Bollard’s Wood, near Stokenchurch, just in Bucks, Rev. A. Robertson 
and E. Armstrong, M.A., 1883, still there in 1885. See Journ. Bot. 1873, 
p. 229. 
Gloster W., Warwick, planted.] 
[P. Phegopteris, L. Gloster E.] 
