Bcrgjuan and Siallard: climax formations 345 



/Ml of these are not found together in any given area or zone, 

 hut in the stage of development from spruce-tamarack swamps to 

 the hnally dominant j^ines, combinations of any two or more of these 

 may occur. By aggregation, families or colonies of any one of the 

 above may occur and are frequently encountered. Pure dominance 

 of any of them is rare. 



Secondary species : Characteristic undershrubs of this associes 

 are: 



Acer spicaUim Rhaniniis alni folia 



AInits incana Rhus rydhergii 



Cornits stolonifera Ribes americanum 



lOorylits rostrata Ribes hudsonianiim 



Lonicera hirsuta Ribes prostratum 



Lonicera oblongifolia Rosa acicularis 

 Parthenocissiis quinqnefolia Viburnum lentago 



Prunus pennsylvanica Viburnum pubescens 

 Prunus virginiana 



Semi-woody plants such as Diervilla lonicera and Rubus triflorus 

 are usually present. 



Amelanchier oblongifolia and Sorbus americana occur occasion- 

 ally. Lonicera oblongifolia and the last two species of Ribes persist 

 from the preceding associes, or from it may invade the adjacent 

 Abies-Betula associes. In some places Rosa blanda replaces R. 

 acicularis. 



The following herbs are commonly found : 



Aralia nudicaulis Equisetmn sylvaticum 



Carex tenella Galium trifiorum, 



Car ex trisperma Maianthemum canadense 



Clintonia borealis Mitella nuda 



Cornus canadensis Rubus triflorus 



Dryopteris cristata Streptopus roseus 



Dryopteris phegopteris Trienfalis americana 



Occasional plants of Actaea rubra may be found with the above. 



(8) Pintis Association 



The further filling of a swamp by the carrying in of soil from 

 the sides and by the accumulation of decayed plant-remains brings 

 about a reduction of the water-content of the soil. The habitat ha? 



