An Ecological Study of Buckeye Lake. 25 



are generally found in cultivated fields or in much drier situa- 

 tions as along railway tracks, but which here grow on a mud 

 flat closely associated with river bank and marsh plants. These 

 are Equisetum arvense, Dipsacus sylvestris, Pastinaca sativa 

 and several species of Labiatae. 



IV Ruderal Herb Association. 



I. Ruderal herb society. Viola papilionacea, Erigeron an- 

 nuus, Dipsacus sylvestris, Oxalis stricta, O. cymosa, Solanum 

 nigrum, S. dulcamara, Equisetum arvense, Homalocenchrus ory- 

 zoides a straggler from the outer zone, Eleocharis obtusa, Juncus 

 tenuis, Eupatorium purpureum, E. perfohatum. Verbena hastata, 

 Phleum pratense, Poa pratensis, Achillea millefolium, Angelica 

 atropurpurea, Mentha piperita, M. spicata, Geum canadensis, 

 Verbesina squarrosa, Teucrium canadense and Lysimachia 

 numularia at the margin of the tree zone. 



This society shows greater seasonal changes than the others. 

 Early in the spring, Viola papilionacea is one of the dominant 

 species, in the latter part of June it is difficult to determine which 

 are the dominant species, for the larger, coarser and therefore 

 more conspicuous plants as the Teasel, Verbena and Eupatorium 

 are about half grown and not dominantly prominent. A month 

 later they overshadow all the others. 



V. Mesophytic-forest association : This association in- 

 cludes two very distinct societies. A Salix society which oc- 

 cupies the filled ground bordering the creek and at the head of 

 the marsh and an Ulmus-Fraximus society bordering the lake and 

 of the same type as the original swamp forest. 



I. Salix society. A zone of willows borders the banks 

 of the creek from the Typha zone to and into the cultivated 

 fields south of the lake. At the edge of the Typha zone it is 

 a narrow fringe of willows on the immediate banks of the 

 stream, toward the head of the cove it broadens into a belt 50 

 feet wide on either side of the stream and finally merges into 

 the tree border of the lake. Where it broadens it is open with 

 scattered clumps of willows, shrubs and a luxuriant ground 



