This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Cuscuta 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 partway 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.