iJ2 UNIVERSITY OF MISSOURI STUDIES [214 



aviculare, P. erectum, P. littorale, Anthemis Cotula, Nepeta 

 Cataria, Sida spinosa, and various weedy grasses, are character- 

 istic. Escapes are common, such as Ornithogalum umbellatum, 

 Asparagus officinale, and Linaria Linaria. 



1. Ruderales malvoides. The mallow association oc- 

 curs principally in barnyards and old lanes. Malva rotundifolia 

 grows in dense patches, but smartweeds {Polygonum spp.), 

 sticktights (Bidens spp.), and Panicum Crus-galli are common 

 also. 



4. Fugitivae. Escapes. There is but one association 

 of escapes that calls for notice. Usually these plants are scattered 

 about in the various societies, but whatever their persistence, 

 they appear always as strangers. 



a. Fugitivae glechomoides. The ground gill associa- 

 tion of creeping herbs is found in the neglected parts of old ceme- 

 teries, in old yards, and about houses in damp shady places. 

 Such plants are Glechoma hederacea, Lysimachia Nummularia, 

 and Vinca minor. The cypress spurge (Euphorbia Cyparis- 

 sias) is frequent also in such places. 



9. LITEBATUBE. 



Blankinship, J. W. The plant formations of eastern 

 Massachusetts. Rhodora 5, 124-137, 1903. 



Bray, W. L. The ecological relations of the vegeta- 

 tion of western Texas. Bot. Gaz. 32, 99-123, 195-217, 263- 

 291, 1901. 



Clements, F. E. The development and structure of 

 vegetation. Univ. of Neb., Bot. Surv. of Neb. 7, 1904. 



Coulter, S. M. An ecological comparison of some typ- 

 ical swamp areas. Mo. Bot. Gard., Report, 15, 39-7 1, 1904. 



Coville, F. V. Botany of the Death Valley expedition. 

 U. S. Nat. Herb. Contr. 4, 1893. 



