Hill : Penobscof Plants. 281 



The development of this siilvarctic iiora is luncli less pro- 

 iioiiiiced west of Penobscot Bay and the few species which 

 extend beyond this region occnr only in isolated localities. 

 As examples may be cited: , Sediu)! roseum, reaching only 

 to ]\ronliegan ; Carex mh')u(, var. kattegaiensis, to the Boston 

 Basin; Carex maritlma, to jMarshfield, ^^fass. ; and EJi/mus 

 arcnarius, var. vilJosus, to Provincetown, ]\Iass. 



The typical range of these sub-arctic species, which are 

 widespread in the far Xorth but restricted toward their 

 southern limits, is well illustrated by Em pet mm nuinim 

 (Fig. 2). 



HiDsoxiAX Plaxts 



The Hudsonian element of the l)oreal flora in the eastern 

 Penobscot Bay region oifcrs little of phytogeographical in- 

 terest. The species are comparatively widespread through- 

 out the area, occurring in many different habitats and 

 forming a conspicuous part of the vegetation. The plants 

 of this zone frexjuently grow in company with sub-arctic 

 types in such habitats as sea cliffs and sphagnum l)ogs. Even 

 more often they are found intermingled with CUmadian or 

 Alleghanian species and might be classified with them were 

 it not for the fact that the Hudsonian flora ranges farther 

 north and so is considered distinct as regards distrilmtion. 



In order to give a general impression of the Hudsonian 

 element in the flora of the eastern Penobscot Bay region it 

 will be sufficient to mention merely a few of the species 

 which ai'e the most conspicuous in each of several character- 

 istic halntats. 



I'PLAX'L) FOIIESTS 



Drijopferis s/)i)iuhjsa Fi/nt.s (imericana 



Ljjropadium ((uuofiiium liuhus puhescena 



Eqnisefinit si/Jraficum Codius canadensis 



