28 UNIVERSITY OF MISSOURI STUDIES ['7^ 



swamp having a more purely paludose vegetation than the 

 northern, where the uliginose types prevail. 



a. Paludosae caricoides. At the nucleus of the swamp 

 there is a scant society of amphibious plants, such as Typha 

 latifolia, Lophotocarpus calycinus, Alisma plantago, Hele- 

 ocharis palustris and Iris foliosa. Scattered among these 

 are tussocks of coarse sedges. These together with certain 

 non-tussock forming sedges, constitute the chief sward of 

 the swamp. The most frequent are given in the following 

 list: 



Carex conjuncta C. squarrosa 



C. tribuloides C. typhinoides 



C. tenera C. aristata 



C. crinita C. Shortiana 



C. lupulina C. stipata. 



C. Frankii 



b. Paludosae cornoides. Around this nucleus are the 

 remnants of a ligneous society, consisting of Cormis sericea, 

 Cephalantlms occidentalis, Fraxinus nigra, Acer dasycarpum, 

 and Quercus palustris. 



c. Paludosae lobelioides. In the open spaces among 

 these, and where there is some freedom from the coarse 

 sedges and grasses, grows the lobelia association, consist- 

 ing mainly of Lobelia cardinalis and L. syphilitica, Mimulus 

 alatus, and species of Lycopus. 



d. Paludosae leersioides. The low levels of the south- 

 ern portion of the swamp are occupied by the rice cut- 

 grass association, which forms an almost impenetrable tan- 

 gle four to six feet high in autumn. The plants have rough 

 stems and cutting leaves, or are twining or recumbent. The 

 following are the chief species : 



