52 BULLETIN 1201, U. S. DEPARTMENT OF AGRICULTURE. 



Europe and is not at the present time a commercial product in this 

 country. The white and the green are the two commercial varieties, 

 the white being largely imported, and the green the American plant. 

 For insecticidal work these two varieties are considered equally 

 valuable. The American hellebore (Veratrum viride), called 

 ' swamp hellebore,' ' Indian poke,' and ' itch-weed,' is a common 

 plant in wet ground and grows over a considerable area of the United 

 States. The properties of this are said to be similar to those of 

 white hellebore." 



Verbascum blattaria L. Sceophueabiaceae. Moth mullein. United States, 

 naturalized from Europe. 



The writers' results are given on page 24. 



Verbascum thapsus L. Common mullein. Europe and Asia, naturalized in 

 the United States. 



Riley (71, p. 185) states that an alcoholic extract and a decoction 

 of the leaves were ineffective against cotton caterpillars. 



Vernonia anthelmintics (L.) Willd. Asteeaceae. East Indies. 



Greshoff (SI, p. 92), quoting Watt, says that the bruised seeds are 

 largely employed as a means of destroying pediculi. 



Vernonia noveboracensis (L.) Willd. Common iron weed. Eastern United 

 States. 



Riley (71, p. 186) states that the alcoholic extract and decoction 

 were ineffective against cotton caterpillars. 



Vitex agnus-castus L. Veebewaceae. Lilac chaste-tree. Mediterranean re- 

 gion. 



Greshoff (33, p. 136) reports that " flies are believed to avoid the 

 tree, so that when they annoy people, branches of this tree are hung 

 in the huts." 



Weeds. (Species not stated.) 



Thibault (89), after determining that insect powder would kill 

 mosquito larvae merely by being spread on the surface of water, then 

 made a powder from weeds and grasses in the neighborhood and also 

 found this powder to be an efficient mosquito larvicide. He decided 

 that powders thus used killed mechanically, rather than by poisoning 

 the larva?. 



Withania somnifera Dunal. Solanaceae. Mediterranean region. 

 Greshoff (33, p. 11+3) lists it as an insecticide. 



Xanthlum strumarium L. Asteeaceae. Cocklebur. Europe and Asia, natu- 

 ralized in the United States. 



Riley (71, p. 184-) says that a decoction and an alcoholic extract 

 had no effect on cotton caterpillars. 



Ximenia americana L. Olacaceae. Synonyms : X. inermis L., X. spinosa 

 Salisb. Wild-olive. Tallow-nut. Tropical regions. 



Greshoff (31, p. 32) reports that " the crushed rind is frequently 

 applied by the negroes in Africa to the sores of domestic animals to 

 keep off the fleas." 



