132 4. CRUCIFERiE. 



Range of mean annual temperatme 46 — 36. 



Native. Rupestral. A mountain species in Britain ; 

 yet descending low down, even in England (say, to 200 or 

 250 yards) , on limestone rocks ; and on the limestones of 

 Sutherland it descends to the sea cliffs. But, like other 

 plants which are obviously influenced in their distribution 

 by the contiguity of limestones, this one does not appear 

 to be quite restricted to calcareous rocks. Mr. Tatham 

 says that it is " abundant close to Settle ;" but I know not 

 whether this means on the same level (less than 200 yards 

 of altitude) as that town. In the midland Flora, the 

 neighbourhood of Buxton is given as a locality for this 

 species, on the authority of the Rev. Mr. Bree : is that lo- 

 cality correct ? 



78. Draba muralis, Linn. 



Area 1 * (3) [4] 5 * 7 8 * 10 * 12 * (14) [15]. 



South limit in Somerset and Staffordshire. 



North limit in Yorkshire and Westmoreland. 



Estimate of provinces 6. Estimate of counties 6. 



Latitude 51 — 55. Local type of distribution. 



Agrarian region. Liferagrarian (?) — Superagrarian zones. 



Descends to } 



Ascends to 200 or 300 yards, in N. England. 



Range of mean annual temperature (say, 48 — 45) ? 



Native. Rupestral. Reported from the counties of 

 Somerset, Stafford, Montgomery, Derby, York and West- 

 moreland; also from the neighbourhood of Chelsea and 

 Edinburgh, doubtless through the botanic gardens of 

 those places. To these we must add the Warden Hills, in 

 Bedfordshire, and the vicinity of Forfar; but I am not 

 aware that these two latter localities have been confirmed 



