32 UNIVERSITY OF MISSOURI STUDIES [164 



Alopecurus geniculatus C. diandrus 



fulvus C. acuminatus 



Eragrostis hypnoides Carex Frankii 



Cyperus flavescens 



c. Limosae juncoides. The rush association of spar- 

 ingly leaved grass-like plants, seldom growing in dense mats, 

 but rather in stools at intervals of several inches, occurs not 

 only at the water-line, but also in flats subject to inundation. 

 They stand in a cold sour soil, which often produces little else, 

 except the autumnal smartweeds. The larger rushes are more 

 properly classed with the palustrous vegetation. Excluding 

 these, the limose species are three : 



Juncus acuminatus J. nodosus 



J. scirpoides 



d. Limosae heterantheroides. The mud-plantain as- 

 sociation of broad-leaved shore plants consists chiefly of Heter- 

 anthera reniformis together with Alisma Plantago and the Sa- 

 gittarias. Plantago cor data also occurs locally. 



e. Limosae ludwigioides. The water-purslane associ- 

 ation of creeping, often succulent plants of muddy shores is 

 found not only at the shore-line, but also in the beds of dried 

 up puddles and pools, or in similar streambeds with mucky bot- 

 toms. Of the following only the first is vernal : 



Ranunculus septentrionalis Rotala ramosior 



Callitriche Austini (water- Ammannia coccinea 



works reservoir) Ludwigia palustris 



f. Limosae gratioloides. The false pimpernel associ- 

 ation of low dift'use herbs, which occupy the spaces left vacant 

 by the rushes and spike-rushes, forms a slight, but well-marked 

 vegetation. These are characteristic: 



Ranunculus abortivus N. palustre 



Nasturtium sinuatum N. sessiliflorum 



(Missouri river.) 



