I 



Jennings : A Botanical Survey of Presque Isle. 359 



This formation consists so largely of the grass-like facies that it 

 conveys at once the impression of a wet meadow. The structure of 

 the formation is simple, but there is a very distinct succession of the 

 two facies. The Cladiian mariscoides consocies always appears first, 

 and usually it has the Sahbatia-Limun formation suppressed before 

 the appearance of Caiatnagrosds canadensis. In older structures the 

 Cladium has entirely disappeared, leaving the Calamagrostis cana- 

 densis consocies in undisputed possession. The later appearance of the 

 Calamagrostis depends probably upon the accumulation of certain 

 amounts of humus in the soil. 



Usually contemporaneously with the appearance of the Calamagrostis 

 there appears in the upper portion of the consocies a zone character- 

 ized during the autumn aspect by Aster ericoides, thus constituting an 

 Aster ericoides society. Often associated with the Aster is Eqiiisetitm 

 hyemale. In places the Aster ericoides society becomes very promi- 

 nent and almost entirely dominates an upper zone of the formation. 



Of the other secondary species mentioned in connection with the Cla- 

 dium- Calamagrostis formation the Cyperus is more largely associated 

 with the Cladium maris coides Q.on?,oc\ts, while the Dryopteris, Asclepias, 

 and Hypericum are found with the Calamagrostis. 



This formation, essentially a wet meadow, which is rarely or never 

 submerged, occupies comparatively large areas around Lagoons E, F, 

 and Fa, and in the older portions of the peninsula is represented by 

 the Calamagrostis canadensis consocies, as around Lagoon B, and in 

 the three marshy areas between B and Horse-shoe Pond. Lagoon Y is 

 now essentially such a wet meadow with, however, some Phragmites 

 in the moister portion and a border of shrubs on the landward side. 



The Myrica-Salix Formation. 

 The Myrica-Salix zone of shrubs has at this stage attained its greatest 

 development, and will soon be supplanted by another shrub-formation 

 characterized by taller and more rapidly growing species. This suc- 

 cession is apparently made possible by the accumulation of humus in 

 the soil, and perhaps also by the protection offered the young seed- 

 lings by the brushy growth of Myrica. The structure of the Myrica- 

 Salix formation at its culmination is not essentially different from its 

 structure as described for Stage D, excepting that invasion by the next 

 formation has begun, as is evident from the presence here of Alnus 

 incana and Rhus typhina. 



