416 Proceedings Portland Society Natural History 



terraediate conditions of drainage, as in poorly-drained 

 areas, there occur intermediate conditions in the vegetation. 

 Such places show similarities to ordinary swamps on the 

 one hand and bogs on the other, and also grade into the up- 

 lands. 



This mingling of species of several different association 

 types is particularly marked where trees occupy the area. 

 One such poorly-drained tract on Naskeag Point in Brook- 

 lin (Figure 4*4) may be described as typical. The ground 

 in this locality is slightly undulating, with shallow depres- 

 sions in which water may be present for a good part of the 

 summer, alternating with higher places. The characteris- 

 tic trees present are the larch, balsam fir, red spruce and 

 white cedar, with an undergrowth of Rhododendron cana- 

 <Jctise, Kalmia angustifolia, Viburnum cassinoides. Ledum 

 groerilandicum and Nemopanthus mucronata. In the low 

 wet places sphagnum, particularly Sphagnum palustre, is 

 abundant and growing with it are the snowberry (Chiogenes 

 hispiduld) and cranberry ( Vaccinia m niacrocarpon ). An 

 adjacent portion of the forest floor may be slightly higher 

 and here the sphagnums are absent while Cornus canaden- 

 sis, Linnaea borealis var. americana, Gaultheria proeum- 

 bens, Lycopodium annotinum and Aralia nudicaidis are the 

 most conspicuous species. 



Another frequently occurring association-type is found 

 in localities which are poorly-drained, but have water pres- 

 ent only at infrequent intervals. After a rain, water col- 

 lects in pools and may be abundant enough to submerge the 

 vegetation, but this surface water evaporates during dry 

 weather and the area may become quite dry. In such situ- 

 ations there is a scattered growth of shrubs alternating with 

 grasses and sedges and considerable sphagnum. By far the 

 most common species is the steeple-bush (Spiraea tomen- 

 tosa), which is so universally present as to be a good indi- 

 cator of this type of habitat. Alnus incana is also fre- 

 quent, as are the following herbaceous forms 



