DESCRIPTIVE MANUAL 235 



Spreading Dogbane {Apocynvm, androsaemifolium L.)- 



Description. — Root-stock horizontal, smooth, or rarely soft-tomen- 

 tose, branched above, spreading, leaves ovate, petioled, cymes loose, 

 spreading, both terminal and axillary; the latter pale rose color, 

 open, bell-shaped; calyx segments shorter than the tubes of the, 

 corolla. 



Distribution. — Common along borders of thickets from eastern 

 Canada to British Columbia to Arizona and Georgia. Abundant 

 in Iowa in grain fields near thickets. 



Fig. 135. Distribution of Spreading Dogbane (.Apooynum anchrosaemifoliiMn). 



Extermination. — Spreading dogbane produces long, creeping 

 roots, which are quite tenacious of life. In order to destroy the 

 weed, the field should be given a shallow plowing after the grain is 

 harvested, followed by a disking in a week or ten days, depending 

 on the character of the weather. This should be followed by a 

 harrow. If the fall is dry dragging will probably get the larger 

 number of these weeds. 



Indian Hemp {Apocynum cannabimim L.). 



Description. — Glabrous or more or less softly pubescent; 2-3 ft. 

 ,high, smooth, terminated by an erect, close, many-fiowered cyme; 

 corolla lobes nearly erect, the tube not longer than the lanceolate 

 segments of the- calyx, greenish white ; appears in July and August. 



Distribution. — Common species eastward and troublesome as a 

 weed in northern Mississippi valley. Common in small-grain fields 

 and pastures. 



