CONVOLVULACEAE (CONVOLVULUS FAMILY) 327 



not be carried about because of the danger of infection. Culti- 

 vated crops should then be grown for some years before the land 

 is again used for clover or alfalfa. 



Spraying with Arsenite of soda has been found in some cases to 

 be satisfactory, a solution of one pound of the poison to ten gallons 

 of water being used. The clover and the alfalfa were also much 

 injured, seemingly killed by the treatment, but recovered and made 

 new growth from the roots after having been relieved from the 

 strangler's grip. A twenty-per-cent solution of Iron sulfate has 

 also been found to be effective on alfalfa fields, killing the parasite 

 and apparently destroying the crop; but, as with the arsenical 

 treatment, new growth sprang from the roots. 



FLAX DODDER 



Ctiscuta Epilinum, Weihe 



Introduced. Annual. Propagates by seeds. 



Time of bloom: June to August. 



Seed-time: Late August to October. 



Range : Wyoming, Idaho, the Dakotas, and other states where flax 



is cultivated. 

 Habitat : Flax and alfalfa fields. 



The coiling stems of this species have somewhat less of the 

 reddish tinge that characterizes the Clover Dodder. The flowers 

 are yellowish white, and the tube of the small, five-lobed corolla 

 does not spread like a bell but is often slightly constricted just 

 below the lobes like the mouth of a vase ; stamens included ; 

 scales short and broad, notched at apex and toothed only part- 

 way down the sides. The seeds are very much smaller than the 

 flax seeds, of course, and might very readily be removed from 

 them if it were not for a habit that this Dodder has of dropping 

 seeds in pairs, which cohere, making them nearly as heavy as 

 those of the flax, though of different shape. But seed from 

 Dodder-infested flax fields, if intended for sowing, should be 

 rejected at any price, and even when intended for linseed-oil 

 manufacture, flax-seed should be very carefully cleansed from all 

 contamination of Dodder-seed. 



Means of control the same as for Clover Dodder. 



