baker's north YORKSHIRE. 



direction of the Central Valley of the southern Howardian ter- 

 race. In the Central Valley the Derwent flows due south till it 

 leaves the Riding, Buttercrambe Moor is a low wooded heath, 

 of the same kind as several which come within the district 

 drained by the Foss. Here grow Cardiius pratensis, Cladiiim 

 Mariscus, Polypolium Phegopteris, and Lastrcza Thelypteris. At 

 Stamford Bridge the river enters the East Riding. 



This is considerably the largest drainage district of the nine, 

 and has considerably the largest flora. In Montane plants it 

 is above all the other districts of the eastern subprovince, but 

 below each of the three hilly districts of the west. For Xero- 

 philous plants it is on a par with the Yore and West Swale 

 districts, and amongst the thick woods and grassy banks of its 

 calcareous hills many of the more interesting plants of this cate- 

 gory grow plentifully. In Maritime plants it is not rich, especially 

 when the length of its coast-line is considered. The Vale of 

 Pickering furnishes a large number of Hygrophilous species, 

 and for Rarer Ascending plants this district stands highest of 

 the nine. 



GEOGRAPHICAL ANALYSIS 

 OF THE FLORA OF THE DERWENT DISTRICT. 

 AREA 515 SQUARE MILES. 



CATEGORY. 



Number of Species. 



Per Centage of 

 total native flora. 



I Montane Species 



40 



47 

 20 



65 

 362 

 166 



34 

 70 

 22 



5 

 6 



3 



9 



49 



23 



5 







5 General Ascending Species 



6 Scattered Ascending ,, 



7 Local Ascending ,, 



8 Colonists 



9 Denizens 



Total number of species. 



827 



