ECOLOGICAL CROSS SECTION OF THE MlSSISSIPn. 201 



est to note that such escapes are most frequent in the vicinity 

 of dwellings occupied by people of German origin. Such 

 plants arc Coriandrum sativum, Foeniculum officinale, Marru- 

 bium vulgare, Melissa officinalis and Nepeta Cataria. Fago- 

 pyrum esculentum and Cannabis saliva frequently are found 

 in waste places where they maintain themselves against 

 great odds. Cichorium Intyhus which, according to Pam- 

 mel*, was introduced near Dorchester, Mass. in 1875 and 

 since then has spread chiefly through the northern states, is 

 frequent along the roadsides on the IHinois plateau, an evi- 



dent 



scape from cultivation. As transient garden esc; 

 be considered Nymphaea reniformis, Citrullus vulg^ 



Citrullus ovifera pyriformis, Centaurea Cyanus, Coreopsis 

 tinctoria, Matricaria Chamomilla, Nicandra physaloides and 



Zea Mays. • 



The transient weeds are Argemone alba, Argemone platy- 

 ccras, Camelina saliva. Sisymbrium altissimum, Cleome in- 

 tegrifolia, Hibiscus Trionum, Medicago lupulina, Petalostemon 

 villosus, Pluchea camphor ata, M artynia proboscidea and Phalaris 

 canariends. Naturally there are a number of other plants 

 which from time to time are introduced through the agencv 



man 



especially among nursery stock. Such plants are 

 most frequently met with in parks and nurseries but are 

 not of sufficiently frequent occurrence to attract attention, 

 the number of individuals being limited. An exception to 

 this rule proved one of the Cyanophyceae, determined by 

 Professor W. A. SetchcU as Osdllatoria Agardhii,^ and new 

 to North America, specimens of which occurred in so large 

 quantities in one of the ponds of the Missouri Botanical 

 Garden, as to form a water bloom. The pond in which these 

 plants were found communicates by a drain with the ponds 

 of Tower Grove Park and it is more than probable that the 

 plant was introduced with water lilies obtained for the park 

 from eastern dealers who imported European stock. 



The introduced established weeds include Clematis crispa. 

 Delphinium Consolida, Chelidonium majus, Sisymbrium of- 



■ 



* Pammel, L. H. Ecology. 335. 1903. 



t Collins, F. S., I. Holdeii and W. A. Setchell. Phyc. Bor. Amer. 30 : 



1451. 1908. 



