indicator here of a stage of vegetational development approximating the 

 climax. 



On formerly cultivated damp soils, sedges, rushes, grasses, and other 

 native herbs quickly form a dense cover. This, in turn, is frequently in- 

 vaded "by sweet gum ( L i qu i dambar styreciflu a) , which locally forms pure stands 

 as dense as the pines on well-drained sites. Further stages in this line 

 of succession have not been studied. 



.Plant communities are of numerous and often complex types, "because of 

 the many, variations in soil, sites, and other environmental factors, and 

 "these are further complicated by man's drastic disturbance of the original 

 vegetation. Their exact definition and their relationships to each other 

 remain to "be investigated. A "brief description, however, will indicate 

 the dominant vegetation, grouped in 10 plant communites, as follows: (l) 

 .water; (2) marsh; (3) wet meadow; (4) shrub s\vamp; (5) swamp forest; (6) 

 bottom-land forest; (7) terrace forest; (8) slope and upland forest; (9) 

 abandoned fields; and (10) hedgero^'rs and woods margins. 



1. ^ater. — Aquatic plants are ra.re on the refuge, because of the 

 heavy shading of most of the waters by trees, the swiftness of the river 

 and the brooks, and the impermanence of water in the shallow bottom-land 

 runs. The species that have been found are sufficiently interesting as 

 indicators of soft- or acid-water conditions to be listed as follows: 



Potamogeton epihydrus — river. 

 P. pusillus — brook. 

 Heteran there, reniformis — pond. 

 Podostemum ceratophyllum — river. 



Callitriche heterophylla — springs 



and runs. 

 Utricularia geminiscapa — brook. 



2. Marsh . — The areas in marsh are small but widely scattered. Marsh 

 plant.s occur along narrow bottom-land runs for short distances, in and 

 along the brooks, and in openings in and along the margins of shrub swamps. 

 The commonest species are: 



Isoetes engelmanni 

 Sparganrum spp. 

 Sagittaria pubescens. 

 Echinochloa crusgalli. 

 Leersia oryzoides. 

 Carex lupulina. 

 C. typhi na. 

 Eleocharis obtusa. 

 Juncus spp . 

 Polygonum arifolium. 

 P. hydropiperoides. 

 P. punctatum. 



Polygonum sagittatum. 

 Nuphar advena. 

 Hanuncul us 1 axi c aul i s . 

 H. pusillus. 

 Hypericum mutilum. 

 H. virginicum. 

 Viola lanceolata. 

 Ludvigia. palustris. 

 Proserpinaca palustris. 

 Lye opus spp. 

 Bideris connata. 



