indicator here of a stage of vegetational development approximating the 

 climax. 



On formerly cultivated d"mp soils, sedges, rushes, grasses, and other 

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

 vaded "by sweetgiim ( Liquidambar sty rscif l ur) , which locally forms pur ~ ads 

 as dense as the pines on weli-drc.ined rites. Farther stages in this li 

 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 he investigated. A brief description, however, will indicate 

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

 water; (2) marsh; (?) wet meadow; (4) shrub swamp; (5) swamp forest; (c) 

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

 abandoned fields; and (10) hedgerows and woods margins. 



1. jVat_er. — Aquatic plants are rare 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 follov.*s: 



Potamogoton epihydrus — river. 

 P. pusillus — brook. 

 Heteranthera reniformis — pond. 

 Podostemum ceratophyllum — river. 



Callitriche heterophylia — springs 



and runs. 

 Ut riculari a gemi ni scapa — b ro ok . 



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

 plants 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 

 Sparganium spp. 

 Sagittaria pubescens. 

 Echinochloa crusgalli. 

 Leersia oryzoides. 

 Car ex lupulina. 

 C. typhi na. 

 Eleocharis obtusa. 

 Juncus spp . 

 Polygonum arifolium. 

 P. hydropiperoides. 

 P, mnctatum. 



Polygonum sagittatum. 

 Nuphar advena. 

 Ranunculus laxicaul i s . 

 R. pusillus. 

 Hypericum mutilu . 

 H. virgin! cum. 

 Viola lanceolata. 

 Ludvi gi a palu s t ri s . 

 Proserpinaca palustris. 

 Lye opus s . 

 Bi dens connate . 



