208 
The Ohio Naturalist. 
[Vol. XI, No. 1, 
The forest formation extends across the island from margin to 
margin and presents two distinct zones : 1 . A border zone 20-50 
feet wide, consisting in part of large trees, the remnant of the 
original forest. It is a very open border, not more than three 
trees deep, the tallest of these trees having attained a height of 
60-65 feet. The shrub stratum is very poorly developed. It is rep- 
resented on the south side by a few Cornus, Rosa and Cephalanthus, 
at the outer margin of the zone; these are wanting on the north side. 
The field stratum is composed almost wholly of grasses of which 
Muhlenbergia diffusa, Agrostis perennans and Syntherisma san- 
guinalis and linearis are the principal species. Associated 
with these is a scanty growth of herbs; and on the south side an 
abundant growth of Rhus toxicodendron, Parthenocissus quinque- 
folia and Vitis vulpina, trailing over the ground. The Rhus has 
also climbed two Ulmus americana. The grass and weeds have 
been mowed, so that the shrubs too are kept in a stunted condition. 
Surrounded by the older forest zone lies a rejuvenated area 
clothed with young forest trees, among which Ulmus Americana 
predominates, fully nine-tenths of the trees are of this species. 
This is a part of the area which was cleared sixteen years ago ; but 
the forest has again invaded the area and become established. 
The ground slopes gently toward the southeast and more abruptly 
toward the northwest. The elevation of the highest portion is not 
more than 4 or 5 feet above the standard water level. The gentle 
slope and the thin shade of the young trees, together with the 
loose light soil, provide a dry sunny habitat on which Carduus, 
Aster, Arctium, Hedeoma, Nepeta, Erigeron and other sun loving 
plants find a congenial environment. There were the remains of 
large Burdocks and large Rubus nigrobaccus canes. There are 
scarcely any grasses in this central area ; and as it has been mowed 
and burned all the herbage is scanty. 
On the northwest margin of the transect the forest formation 
is followed immediately by the marsh-herb formation. The 
marsh-shrub formation is wanting. The marsh-herb formation is 
represented by four societies: 
8. Hibiscus moscheutos society, 
9. Polygonum-Scirpus society, 
10. Scirpus lacustris society, and 
11. Nelumbo-Potamogeton society, none of which shows the 
development of the marsh zones on the south side. 
8. Hibiscus moscheutos society. 
Facies. 
Hibiscus moscheutos. 
Secondary species. 
Hypericum mutilum. 
Impatiens fulva. 
Hedeoma puligioides. 
Panicum walteri. 
Bidens cernua. 
Xanthium canadense. 
Rosa Carolina. 
