176 BOTANICAL GAZETTE [MARCH 
black oak is usually the chief character tree. No satisfactory 
reason can yet be given for these variations, though the bur 
oak appears to be more abundant on the lower and less drained 
ridges, while the black oak is more abundant on the higher 
ridges. The shrub undergrowth is commonly sparse, and the 
most frequent members of this stratum are the hazel (Corylus 


35.— Portion of an ancient beach (Glenwood beach) near Thornton. The 
trees here are chiefly black oaks (Quercus coccinea tinctoria) ; the beach is higher, and 
the trees more luxuriant than usual. 
Americana), Rosa, the New Jersey tea (Ceanothus Americanus ), 
Salix humilis, the low blueberry ( Vaccinium Pennsylvanicum) , 
and the huckleberry (Gaylussacia resinosa). Among the com- 
moner herbs are Silene stellata, Antennaria plantagintfolia, Heu- 
chera hispida, Rumex Acetosella, Carex Pennsylvanica, Potentilla 
argentea, Poa compressa, Pteris aquilina, Ceratodon purpureus. In 
open places there are often almost pure growths of Poa or 
Potentilla. Figs. 34 and 35 show portions of these ancient 
beaches in which the oaks dominate; jig. 34 shows, perhaps, the 
more common condition, 7. ¢., a rather low beach with a sparse 
tree growth. 
