208 



WEED FLORA OF IOWA 



Fig. 120-A. Distribution of Spotted Spurge. 



frequently falcate, serrate, generally with a conspicuous red spot, 

 or margin ; flowers pedunculate in terminal cymes ; appendages en- 

 tire ; pod glabrous ; seeds ovate sometimes wrinkled. 



Distribution. — In loose soils and fields from New England and 

 Canada to Wisconan, Minnesota and Nebraska, also southward. 



Extermination. — This annual weed is easily exterminated by cul- 

 tivation ; therefore practice rotation of crops and give thorough cul- 

 tivation. Seeds of several species of this genus retain their vitality 

 for some length of time. 



Milkweed or Creeping Spurge {Euphorbia maculata L.) . 



Description. — Slightly pubescent or hairy annual, with prostrate 

 stems; leaves oblong-linear, oblique at the base; pubescent or some- 

 times nearly smooth, usually with a brown-red spot in the center; 

 serrulate above, stipules lanceolate ; flowers pedunculate in lateral 

 clusters; glands of the involucre minute; appendages usually red; 

 pods .acute-angled; seed sharply 4-angled with 4 shallow grooves 

 across the sides ; trichomes several-celled, gradually tapering to apex. 



Distribution.— ¥ovoa.di in sandy fields, or generally in fields from 

 New England and Canada westward; common in every part of 

 Iowa. 



Extenmnation.- 

 preceding species. 



-May be exterminated in the same way as the 



