Hill: Penobscot Vegetation 407 



Carex filiformis Aster nemoralis 



Carex rostrata Aster radula 

 Xyris montana 



Shrubs 



Myrica Gale Gaylussacia dumosa var. 

 Pyrus melanocarpa Bigeloviana 



Xemopanthus mucronata Vaccinium macrocarpon 



Ledum groenlandicum Vaccinium Oxy coccus 



Chamaedaphne calyculata Lonicera caerulea vars. 



Kalmia Polifolia Viburnum cassinoides 



Trees 

 Larix laricina Picea mariana 



Picea rubra Acer rubrum 



In general the bogs fall into two classes depending on 

 whether or not the mat completely fills the depression in 

 which the bog occurs, the case where a pond still occupies 

 the center of the depression being of most frequent occur- 

 rence. The bogs at Stockbridge and Sadler ponds on 

 Swans Island may be described as typical of such a condi- 

 tion. The ponds in these bogs have the usual aquatic spe- 

 cies and about their margin a fringe of Chamaedaphne 

 calyculata, Myrica Gale and Pyrus melanocarpa which are 

 the chief species concerned in the steady encroaching of the 

 mat on the pond itself. The floating mat is distinctly of 

 the quaking type with sphagnum predominating, and grow- 

 ing in it numerous sedges and low shrubs. The commonest 

 sedges are the various species of Carex, cited in the above 

 list, Rhynchospora alba, and Eriophorum virginicum, while 

 associated with them are most of the herbaceous plants, 

 such forms as Calopogon, Pogonia, Sarracenia, Drosera 

 rotundifolia, Solidago and Aster being conspicuous. The 

 characteristic shrubs on the mat, in addition to the three 

 already mentioned as pioneers, include Kalmia, Gaylussacia, 

 and Lonicera and the cranberries (Vaccinium macrocarpon 

 and V. Oxycoccus). A striking feature of the mats is the 



