Hill: Penobscot Vegetation 329 



per birch. The shrubby growth consists chiefly of mountain 

 maple (Acer spicatum), moosewood (Acer pennsylvanicum) , 

 hobble bush (Viburnum alnifolium), and hazelnut (Corylus 

 rostrata), with numerous seedling hemlocks and spruces and 

 •occasional reproduction of the other species. Considerable 

 balsam fir is present, but only as small undeveloped trees 

 less than ten feet in height. 



Another tract of timber, situated along Craigs Brook in 

 the same town, may also be considered as typical, although 

 it is distinctly second growth and has not attained the age 

 of the preceding stand. Here the beech and sugar maple 

 are most abundant, with the yellow and paper birches and 

 the hemlock less frequent, while the spruces are compara- 

 tively uncommon. As in the area just described, there is a 

 definite second story, or layer, of balsam fir; and a shrubby 

 growth which includes the yew (Taxus canadensis), seedling 

 oaks and hemlocks, as well as the characteristic shrubs men- 

 tioned above. 



A third tract of climax forest, located on the southern 

 slopes of Mt. Megunticook in Camden, shows similar con- 

 ditions, although the trees are restricted to three species. 

 Hemlocks comprise 60% of the individuals, and sugar ma- 

 ple and beech in about equal quantities make up the bal- 

 ance. A peculiar feature of this stretch of woods is the al- 

 most entire absence of shrubby undergrowth. 



In all three of these areas the herbaceous plants are sim- 

 ilar and it is interesting to note that these forms are more 

 northern in their distribution than are the woody species. 

 The following plants may be considered as characteristic of 

 the climax forest : 



Dryopteris spinulosa Oxalis americana 



Dryopteris Phegopteris Viola incognita 



Lycopodium annotinum Circaea alpina 



Clint onia borealis Cornus canadensis 



Maiantliemum canadense Monotropa Hypopitys 



