DESCRIPTIVE MANUAL 



103 



Fig. 5 8- A. Distribution of Mexican Fireweed. 



Distribution. — In waste places commonly cultivated and now a 

 frequent escape in Iowa. Common in many of the northern states, 

 Rocky mountains and the Pacific coast. From eastern Europe and 

 western Asia. 



Extermination. — This weed is easily exterminated by cultivation. 



Mexican Tea (Chenopodium ambrosioides L.). 



Description. — A smoothish annual, or slightly pubescent ; strong 

 scented ; leaves oblong or lanceolate, entire or cut-pinnatifid, nearly 

 sessile ; spikes densely flowered, leafy ; flowers in small, dense, axil- 

 lary spikes ; calyx 3-parted enclosing the fruit. The wormseed 

 (0. anthelminticum) is an annual or sometimes a perennial; leaves 

 more strongly toothed; the flowers usually in bractless panicled 

 spikes. 



Distribution. — Mexican tea is found southward, occurring, how- 

 ever, from Maine to California. The wormseed has nearly the same 

 distribution occuring northward to Minnesota and Wisconsin. 

 Neither of these weeds is common in Iowa. 



Extermination. — In Iowa both of these weeds are easily extermin- 

 ated by cultivation. Do not permit any of their seeds to mature. 



