MICHIGAN WEEDS. 



389 



MILKWEED FAMILY. ASCLEPIADACEAE. 



Perennial herbs or shrubs, mostly having milky juice; flowers too peculiar for beginners, mostly 

 born in umbels; pod one-celled, bearing flat seeds with silky hairs at one end. 



A large family, containing 1,900 species mostly found in tropical or warm temperate regions. 



Fig. 160 (140). • 



Common Milkweed. Asclepias Syriaca L. Stem stout, usually unbranched, finely pubescent, 

 coming from deep, fleshy roots difficult of extermination; leaves opposite, broad, flowers in umbels; 

 pods S-13 cm. long, covered with soft spinous processes. 



A native plant very troublesome on sandy land in the northern part of the state where the crop 

 is undisturbed for more than two years. Occasionally "sick" with a pale, dwarf growth, a bac- 

 terial disease. 



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