26 UNIVERSITY OF MISSOURI STUDIES [l68 



V. riparia Campsis radicans 



Quinaria quinquefolia Lonicera glauca (rare) 



Ampelopsis cordata 



c. Ripariae equisetoides. The riparian horsetail com- 

 munity commonly occurs along all the streams, especially on 

 low clay or sandy banks. Along the Missouri river large tracts 

 are covered with the leafless and branchless stems of Equise- 

 tum hiemale, or less frequently, E. variegatum. E. arvense is 

 frequent also along moist banks. 



d. Ripariae elymoides. The lyme grass, or wild rye, 

 association forms a noticeable fringe of tall coarse grasses along 

 the banks of streams both in and out of shade. Besides the 

 more or less amphibious grasses such as Eatonia Pennsylvanica 

 and Glyceria nervata, the following are characteristic : 



Bromus ciliatus E. Canadensis 



B. purgans E. glaucifolius 



Elymus striatus Asprella Hystrix 



E. Virginicus 



On low banks certain sedges are also common: 

 Cyperus erythrorhizos C. Shortiana 



Eriophorum lineatum C. Frankii 



Scirpus atrovirens C. vulpinoidea 



Carex conjuncta 



It should be added that all but the last of these occur rather 

 with Glyceria nervata than with the lyme grasses and might 

 well form a subassociation of their own, Ripariae elymoides 

 caricinae. 



e. Ripariae silphioides. The cup-plant association of 

 tall, mostly composite plants is found mainly on open stream 

 banks. Besides the typical Silphium perfoliatum, a large num- 

 ber of bone-sets (Eupatorium spp.), ironweeds (Vernonia 



