Dogbane and Milkweed 305 
<S 
Fic. 85.—Trap of the spreading dogbane. 
«, the flower with its calyx and corolla removed, showing the stamens and 
honey-glands ; 4, the opened corolla, showing the callosities; ¢, a trap seen 
from the side; d, the circle of traps, seen from above, 
