35 8 George E. Nichols, 



Carex flava Eupatorum purpureum 



Carcx intiimescens Aster nemoralis 



Carex pallescens Aster puniceus 



Carex paupercula Aster radida 



Carex stellulata Aster timbellatus 

 Habenaria clavellata 



The bryophytes, as a rule, are well represented in open 

 swamps, usually forming a more or less conspicuous understory 

 of vegetation. The following additional species may be men- 

 tioned as characteristic : 



Sphagnum palustre Camptothecium nitens 



Sphagnum imbricatum Rhytidiadelphus squarrosus 



Sphagnum magellanicum Chrysohypnum stellatum 



Sphagnum Girgensohnii Acrocladium cusptdatum 



More often than not, shrubs put in their appearance so early 

 that the wet-meadow stage in the succession is of very brief 

 duration. Frequently it is eliminated as a distinct phase. 

 Instead, there may arise a mixed growth of shrubs and herba- 

 ceous plants : these with scattered trees constitute the most 

 familiar type of vegetation in open swamps. The common 

 pioneer shrub is the alder (Alnus incana). Associated with this 

 may grow any (or all) of the following species: 



Salix humilis Rubus canadensis 



Myrica Gale Rosa nitida 



Ribes hirtellum Ilex verticillata 



Spiraea latifolia Viburnum Opulus americanum 



Rubus pubescens Viburnum cassinoides 



On the whole, ericaceous shrubs (or semi-shrubs) are scarce 

 in well-drained swamps, but Chiogenes hispidula commonly, 

 Kalmia angustifolia frequently, and Chamaedaphne calyculata 

 and Vaccinium macrocarpon occasionally are present. 



The edaphic climax association-type. — Ultimately the entire 

 swamp may become wooded, but, as a rule, much of it remains 

 fairly open, with trees scattered, but more abundant toward the 

 margin, and with the shrubs and herbaceous plants of open 

 swamps occupying the spaces between them. The predominant 

 trees, as a rule, are balsam fir, black spruce, white spruce, and 



