186 MR. G. S. BOTJLOER ON THE PERFOLIATE PENNT-CRESS. 



" Limestone pastures." I doubt whether this species could pos- 

 sibly survive in a pasture. Its radical leaves do not usually form 

 a strong rosette ; and all the spots where I have seen it were com- 

 posed of loose limestone destitute of other plants. If it cannot 

 be termed a " pascual " plant, it tells us little to term it " viatical.'' 

 The exposed situations in which it occurs would render " glareal '* 

 an appropriate term, had not Mr. Watson himself confined it 

 chiefly to sand and gravel. Most "rupestral" plants certainly 

 are "calcophiles ;" so perhaps we must use that term in default 

 of a better. Estimated roughly, the range of altitude I have ob- 

 served is from about 360 feet to nearly 500 feet above mean sea- 

 level. 



The fact of the boundary between Oxfordshire and Gloucester- 

 shire coinciding with that between Watson's provinces of Thames 

 and Severn, and that between G-loucestershire and Wiltshire with 

 that between the Severn and Channel, illustrates very forcibly the 

 unfortunately artificial characters of those provinces, which their 

 author himself points out. 



As a matter of fiict, Professor Buckman's Sapperton locality 

 alone is barely within the Severn basin ; and all the others, inclu- 



Wilt shire 



P.S. 



Will 



records Thlaspi perfoliatum at Burford, Naunton, and Seven 

 Springs, near Stow-on-the-Wold, in 1818 ; and Bagster, in 1839, 

 as abundant at Foss-bridge. In the 6th ed. of 'The British 

 Flora ' of Hooker and Arnott it is also mentioned as occurring 

 on stone walls about Kineton, Warwickshire. In 1844 Professor 

 Buckman, in his 'Botany of Cbeltenliam,' writes, "about the 

 stone quarries, at Kyneton Thorns, Harford Bridge, and the 

 Seven Springs, Naunton. These habitats are perhaps the only 

 ones .... as it has been lost from .... Burford." In Deakin^s 

 ' Florigraphia Britannica ' (1845) " Burford and Upper Slaughter 

 Oxfordshire ; Kineton, Gloucestershire," are given. Kineton is 

 about ten miles from the Warwickshire border, Upper Slaughter 

 almost as many from that of Oxfordshire, both places being in 

 G-loucestershire. There is an unauthenticated record from near 

 Bristol. 



