IBERIS 67 



3. Pang. Bradfield, Jenkinson. Tidmarsh. Biicklebury. Frilsham. 



Pangbourn. Basildon. Purley. Tilehurst. 



4. Kennet. High cornfields near Shaw, Russell's Cat. Aldermaston, 



Bosivell. Mortimei*. Beenham. Ufton. Theale. Padworth. 

 Newbury. Burghfield. Silchester. Common on railway banks 

 between Midgham and Newbury. 



5. Loddon. Common fields opposite Bisham woods, abundantly, 



Ilill. Bisham and Wargrave, Melvill. Wellington Coll. List. 



Between Wokingham and Sandford Mill, Salmon. Wargrave. 



Hurst, Melvill. Maidenhead. Twyford. Early. Waltham. Bray. 

 The plant, although often absent from considerable areas, is widely 

 distributed, and reaches its maximum of frequency in gravelly or clayey 

 cornfields ; in such localities it is found in all the bordering counties. 



**T. PERFOLiATUM, Linn. Sp. PI. 641 (1753). 



Top. Bot. 31. Syme, E. B. i. 203, t. 145. Nyman, 62. Baxt. t. 240. Fl. Oxf. 36. 

 Casual ? Grrassy bank by railway. Very local. A. March- April. 



Mr. T. B. Flower includes it in RoheHson's Env. of Reading, 1843, but the 

 entry is probably an error, for as T. arvense is not mentioned in the list, 

 we may assume that this was the species observed, 



2. Ock. A few plants have been noticed on Cumnor Hill, but these owe 

 their origin to some seed which was scattered there by Messrs. Boswell 

 and Holliday in the year 1861. By the side of the railway near Dench- 

 worth, Rev. W. O. Wait, 1896. 



It occurs in considerable quantity over a limited area on the railway side, 

 which is here composed of gravel brought from the neighbourhood. The 

 plant is not quite identical with the form which occurs on the Oxfordshire 

 quarries, being taller, more erect and less branching in growth ; it resembles 

 specimens which I have seen from Sweden, collected by Ahlberg. Possibly 

 it originates from seeds introduced by passing trains, but where it occurs 

 there is no siding where freight trains could be shunted, and notwithstanding 

 the numerous foreign casuals which I have noticed at Didcot, I have never 

 seen Thlaspi there. The geological character of the country about Dench- 

 worth is Gault, a formation on which one would not expect Thlaspi to be 

 native. 



This very local plant occurs over a very limited area of Oxfordshire, Wilt- 

 shire, and Grloucestershire, the only counties in which it is wild in Britain. 



IBERIS, Linn. Gen. PI. n, 721 (Dill. Gen. 6). 

 I. amara, Linn. Sp. PI. 649 (1753). Candy-tuft. 



Top. Bot. 32. Syme, E. B. i. 207, t. 149. Baxt. t. 351. Nyman, 61. 

 Fl. Oxf. 34. 



Colonist. Agrestal. Chalky fields. Locally common. A. May-Sept. 



First record. In arvis circa Henley et alibi comit. Oxon., Hudson, FL 



Angl. 285, 1778. More definitely recorded as a Berkshire plant in 



E. B. t. 52, where it is said to have been brought from the fields 



about Wallingford by Br. Smith in 1791. 



2. Ock. About Wallingford plentifully and undoubtedly wild, 



Smith, Fl. Brit. 1800, and sp, dated 1791 in Herb. Linn. Soc. See 



F 2 



