DESCRIPTIVE MANUAL 



67 



Fig. 36-A. Distribution of Bunch Flower. 



Extermination. — This weed is common only in native meadows 

 It is killed when these meadows are broken up and cultivated. 



Wild Onion {Allium canadense L.). 



Description. — ^A perennial herb, with small scapose bulb; bulb 

 coat somewhat fibrous; flowers umbellate, umbels densely bulbifer- 

 ous; perianth of 6 divisions which are narrowly lanceolate, as long 

 as the 6 stamens or longer ; capsule 3-celled, not crested ; seeds black. 



Distribution. — Common in moist meadows in many parts of Iowa : 

 Boone, Story, Marshall and Polk counties ; from New Brunswick to 

 Wisconsin, Texas and Florida. 



Extermination. — This weed is common in native meadows, seldom 

 persists like the wild garlic {Allium vineale) of Europe in cultivated 

 fields; thorough cultivation of the field with a plow and disk and 

 cultivator will destroy the weed. 



DICOTTLEDONEAE, DICOTS. 



Stem formed of pith wood and bark ; between the bark and wood, 

 the cambium layer an annual ring of wood formed each year ; leaves 

 netted veined ; flowers generally on tie plan of five ; embryo with a 

 pair of cotyledons. Rose, pigweed, potato, bean, clover, Russian 

 thistle, horse nettle, Canadian thistle belong to this division. 



