All Ecological Study of Buckeye Lake. 45 



alternation or even mixture of several societies of the shore and 

 semi-aquatic associations. Sometimes Peltandra virginica grows 

 in the water at the outer horder and again it occupies the center 

 or even the inner margin of the zone. Thus it is with the other 

 species present. 



In the more sheltered waters along the north shore, and 

 everywhere at the head oi small coves, Tyj^ha holds a con- 

 spicuous place at the water's edge, while the more exposed 

 apices of points of land extending into the water are covered 

 by clumps of Decodon verticillatus, whose long, pendulous 

 branches extend in all directions. (Fig. i6.) AMien they touch 

 the water or mud, the nodes at the point of contact develop 

 roots and anchor the shoot ; the free tip elongates and the re- 

 sult is a Decodon shrub established sometimes 3-4 feet distant 

 from the parent plant. Decodon is best adapted to reaching out 

 and extending the margin of vegetation several feet in advance. 

 The large, thick root stalks and fibrous roots of Ty])ha serve well 

 to gain a foothohl and thus prevent the soil from washing away 

 and by the accumulation of the large stalks and leaves build up 

 the surface level. 



Often the marsh zone is invaded and crossed 1)}- the thicket. 

 Then Rhus and Alnus shrubs or even maple trees grow at the 

 extreme edge of the is'an;!, their roots e:rxo:-ed or under water. 



At other points the marsh extends thru the thicket; or if 

 the latter be vvanting, into the bog-meadow in tongues or 

 isolated patches. The larger pools in the bog are bordered by 

 a fringe of Typha lati folia, Decodon verticillatus and Hibiscus 

 moscheutos. (Fig. 17.) Snmetimes small (lc])ressi()ns hold one 

 or a few Peltandra virginica or Xymphaea advena ])lants. Sagit- 

 taria latifolia is becoming very abundant in the southwestern 

 portion of the bog-meadtnv. 



The characteristic species of the marsh zone are Typha 

 latifolia, Decodon verticillatus, I'eltandra virginica, Ilil)iscus 

 moscheutos, Dianthera americana and Rosa Carolina. In early 

 summer the clumps of Rosa make a rose garden of the swamp; 



