18 



Proceedings of the Ohio State .leadeiiiy of Science 



Sunimerland iieach on the southwest is a rather high, 

 grass-grown point with a thin fringe of trees at the margin, and 

 no marsh zone forming. The cove immecHately to the south- 

 east is low and flat and furnishes an interesting example of the 

 succession of marsh and aquatics by ruderal herl) societies. 

 There is a marginal zone of Polygonum emersum then Xelumbo 

 lutea and Potamogeton lonchites, followed by a Polygonum- 

 Scirpus fluviatilis zone associated with Roripa palustre, Galium 

 asprellum and Hibiscus moscheutos. In this zone the surface 

 has so recently been under water that it is wet and bears many 



IiG. G. — Lakeward side of Cove southeast of Sunimerland Beach. At 

 outer margin is a society of Polygonum emersum, this is followed by a 

 Nelumbo lutea zone which is succeeded by sedges. 



stranded Potamogeton lonchites whose leaves are broader than 

 when in water, and the tips of whose shoots are erect. This 

 zone is followed by a broad mixed belt ; towards the outer mar- 

 gin of which Hibiscus and Scirpus are dominant. There are 

 numerous scattered clumps of Sambucus canadensis, Hibiscus 

 and two Salix nigra, while Polygonum emersum and P. sagit- 

 tatum are abundant. A narrow line of elms crosses it diagonally 

 as though marking a former shore line. This zone is largely in- 

 vaded by ruderal herbs of which Ambrosia trifida, Verbena 

 hastata, Lactuca scariola, L. canadensis, Urtica gracilis, Dip- 



