62 Proceedings of the Ohio State Academy of Science. 



no growth of vegetation underneath. The ferns form a 

 .green border just within the outer edge of nearly the en- 

 tire wooded zone. 



Other areas, generally where the taller trees are most numer- 

 ous, bear a field or low herb stratum of sedges such as Carex in- 

 terior, C. retroflexa, Eleocharis palustris, Dulichium arun- 

 ■dinaceum and other low herbs such as Triadenum virginicum, 

 which in the shade is low and sterile, Boehmeria cylindrica, 

 Adicia pumila, Impatiens biflora, Cardamine bulbosa, Roripa 

 americana, Comarum palustre, Dryopteris thelypteris, D. cristata, 

 Habenaria lacera and H. clavellata. 



Sphagnum sp. forms a ground layer which extends often to 

 the marsh zone. In this are many Rhus, Acer and Aronia 

 seedlings. Immediately beneath the larger shrubs and trees the 

 ground often seems bare but scrutiny reveals a dense closely 

 packed mat of a pure growth of Cephalozia and Pallavicinia 

 lyellii or of Pallavicinia alone. These small Hepaticeae lie so 

 firmly pressed against the ground and are often so dark in color 

 that they have not the appearance of living plants-. Scattered 

 singly, in twos or in threes everywhere thruout the central por- 

 tion of the zone is a small slender herb with pale green thread- 

 like, angled, erect and rigid stems, 3-5 inches tall, with small 

 scale-like leaves and slender spikes of small flowers, a most in- 

 significant little plant, one of the Gentianaceae family, Bartonia 

 virginica, which next to the dominant shrubs and trees, is the 

 most characteristic and abundant plant in the association. 



There are several large pools in the wooded zone ; these are 

 surrounded by marsh plants and bear the same pond vegetation 

 already discussed. 



Between the exposed roots of trees and shrubs and between 

 clumps of ferns are small depressions filled with water. Bryo- 

 phyta as Sphagnum sp. Polytrichum commune or P. ohioense, the 

 water moss Brachythecium plumosum and Pallavicinia lyellii line 

 the sides and bottom of these pools. Spirogyra and other algae 

 float on the water or cover submerged leaves and stems. Viola 

 blanda and Cardamine bulbosa grow in the water or on the mar- 



