. TRANSACTIONS OF WAGNER 



i6 



THE VEGETATION OF THE HACKENSACK MARSH: A TYPICAL AMERICAN FEN 



either isolated individuals, or else they are found in associations forming the 

 marsh thickets, or carr. Quercus bicolor, the swamp white oak, is found in low 

 swales bordering the fens, along with Amelanchier oblongifolia, Pyrus arhuti- 

 folia, Rosa Carolina, Samhucus canadensis, and Acer rubrum, The wild cherry, 

 Prunus serotina, grows entirely isolated in a Phragmites marsh, or it enters 

 the thickets as a rather prominent element (Fig. 7). The Virginia creeper, 

 Psedera quinguefolia, and pigeon grape, Vitis cEstivalis, grow in the carr and 

 clamber over the trees and shrubs, binding them together. The white ash, 

 Fraxinus americana, is an element of moist thickets, as also the black haw. 

 Viburnum prunifolium. These isolated shrubs and trees and the above thickets 

 break the monotonous sky-line. In one or two places along the eastern edge 

 of the marsh the thicket interspaces are invaded by trees and shrubs, so that 

 in a few years, assisted by the artificial drainage which is taking place, the 

 thicket formation will be extended so as to cover large areas of the open fen. 

 Vegetation of Snake Hills. — One other unit of vegetation should be 

 mentioned in closing this account of the formation of the Hackensack Marsh. 

 As previously mentioned by the junior author. Burns, there are two basaltic 

 outcrops, represented by Snake Hill and Little Snake Hill, which support a 

 dry upland vegetation. As they form conspicuous landmarks in the center of 

 the marsh, actually dividing it into an upper and a lower portion, a brief 

 account of the vegetation is appropriate. The trees of the Snake Hills are 

 Juglans cinerea, Betula lutea, Quercus Prinus (abundant), Celtis occidentalis 

 in rocky areas, Sassafras variifolium, Hamamelis virginiana, Liquidambar 

 Styraciflua, Acer saccharum, Comus paniculata. Viburnum pubescens, while the 

 late blueberry, Vaccinium vacillans, forms the common undergrowth layer on 

 these rocky hills. The herbaceous plants of such rocky hills are given in the 

 hst of plants collected by Vincent G. Burns and need not be mentioned here. 



THE FLORA (V. G. B.) 



In view of the fact that the difference between low and high tide levels 

 in the Hackensack River is only 2 or 3 feet, and as one goes up the river the 

 water becomes less salt, it would be expected that the flora would change 

 from a typical salt marsh near Newark Bay, at the river mouth, to a brackish 

 flora in the center of the valley, and finally to a fresh-water flora in the north- 

 ern part. Also it would be expected that, as one went back from the river on 



