2O8 WEEDS OF THE FARM AND GARDEN 



Dogbane Family (Apocynaceac). Perennial herbs, 

 shrubs or vines, with milky or acrid juice and entire, 

 mainly opposite leaves, without stipules ; perfect, regular, 

 five-parted flowers ; five-lobes of the gamopetalous flowers 

 convolute and twisted in the bud ; calyx persistent, lobes 



imbricated in the bud ; 

 stamens as many as the 

 lobes of the corolla, alter- 

 nate with them and in- 

 serted on the tube or 

 throat ; pollen granular ; 

 ovary superior with two 

 distinct ovules; fruit in 

 our genera follicles ; seeds 

 with a large straight em- 

 bryo, often bearing a tuft 

 of hair. One hundred and 

 twenty-five genera and 

 1,000 species, which are 

 very widely distributed, 

 especially in the tropics. 



Spreading Dogbane 

 (Apocynum androsaemifoli- 

 um, L.). Rootstocks hori- 

 zontal, smooth, or rarely 



soft-tomentose ; branched 

 Fig. 134. Wild carrot (Daucus 



Carota). A troublesome weed of above, spreading; leaves 

 the East. (After Harrison and ovate, petioled ; cymes 



loose, spreading, both 



terminal and axillary; calyx segments shorter than the 

 tubes of the corolla, the latter pale rose color, open, bell- 

 shaped. Common borders of thickets from Canada to 

 British Columbia, Arizona and Georgia. 



Indian Hemp (Apocynum cannabinum, L.). Glabrous 

 or more or less soft-pubescent, two to three feet high, 

 smooth, terminated by an erect, close, many-flowered 



