67 



Polygonum lapathifolium L. Slender Pink Persicaria 



Polygonum Persicaria L. Lady's Thumb 



Polygonum Convolvulus L. Black Bindweed 



Polygonum sagittatum L. Arrow-leaved Tearthumb 



Solanum Dulcamara L. Bittersweet 



Urtica gracilis Ait. Nettle 



Verbena hastata L. Blue Vervain 



Verbena urticcefolia L. White Vervain 



The birds characteristic of this habitat are few in number. 

 The Maryland Yellowthroat and the Song Sparrow are the most 

 typical; the Mourning Warbler, the Indigo Bunting, and a 

 few others of varied habits sometimes nest here; and infre- 

 quently the Swamp Sparrow builds thus far away from the 

 sedges. 



Among the mammals, the Star-nosed Mole is the most 

 typical species, but the Jumping Mouse and the Meadow 

 Mouse occur abundantly. The Short-tailed Shrew (Blarina 

 brevicauda) is found occasionally, but it belongs more par- 

 ticularly to the alder-willow and maple-elm associations. The 

 Deer Mouse {Peromyscus leucopus) is found where there are 

 stumps or fallen trees. 



This association is quite rich as a feeding ground, especially 

 in the fall and early spring, as long as there are seeds to be 

 found, for the seeds of the varied assortment of plants occur- 

 ring here are much more available for food than are those in 

 the other societies. 



VI. The Alder-willow Association. 



(Plate V, fig. 2.) 



This might well be considered as two societies, for the alders 

 generally precede the willows in securing a foothold in the 

 marsh. Ornithologically, however, it constitutes a unit. It 

 includes, in addition to the alders and willows, a number of 

 other plant forms, such as the skunk cabbage and the water 

 arum. Toward the swamp, in the more aquatic situations, 

 are the buttonbushes; on the other side, the red osier, wild 

 rose, and meadowsweet. Many of the plants of the preceding 



