4. CRUCIFER.E. 121 



Humber and Trent. Besides these, there is an isolated 

 locality, familiar to Metropolitan botanists; namely, the 

 wall of Eltham church-yard, in Kent; to which it may 

 likely have been introduced. The altitude of 450 yai-ds is 

 intended for the locality of Eglwyseg Craigs, in Denbigh- 

 shire, which are said to have an altitude of 1688 feet; but 

 I do not recollect that the Hutchinsia attains quite to their 

 summit, although it ascends higher than Castle Dinas 

 Bran. Among the species refen-ed mostly to the local type 

 in this work, there are some whose distribution coincides 

 nearly with the Hmestone tracts of the west and north of 

 England and Wales. Geographically, their type is inter- 

 mediate between the Highland and Atlantic. These may 

 ultimately be taken as a small gi-oup of themselves, whose 

 geograpical areas are modified by the natm-e of the rocks 

 on which they grow, more than by climate. The Hutchin- 

 sia may be taken as a fair example of this small gioup ; and 

 Di-aba muralis is another. Thlaspi alpestre comes a step 

 nearer to the true Highlanders, by one outlying locaHty, in 

 Forfarsliire ; and Dryas octopetala is a converse example, 

 of a truly Arctic or Highland species shading off into this 

 group. Cardamine impatiens, notwithstanding its locality 

 in Smrey, essentially belongs to the group. And though 

 extremely local examples, Draba aizoides, Ai-abis stricta, 

 and Thlaspi jjerfoliatum may associate there also. The 

 group may be distinguished as the ' Anglo-Cambrian' sub- 

 division of the local type. 



65. Teesdalia nudicaulis, Br. 



Area 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15. -^ ^^^^/'./J^/. 

 South limit in Cornwall, Hants, Kent. v^z-<<*i/t« 

 North limit in Moray and near Glasgow. /IH^-D tjt^ , 



K 



