﻿Two Phaenogamous Parasites of the Red Clover. 



By Byron D. Halsted. 



J 



usual development of dodder {Cuscuta Epithymum Mum), upon the 

 red clover {Trifolium pratcnsc L.). Extracts from two of the many 

 etters that were received concerning this parasite will indicate the 

 extent of the trouble. " While cutting the clover the machine 

 would suddenly enter a thread-like mass, which clogged it com- 

 pletely * * * The wilted mass formed a sort f blanket which 



could be rolled up. * * * There were about fifteen of these beds 



averaging six feet in diameter to the acre. * * * In these beds 



everything is as dead as if burned over with fire." From another 



letter it is gathered that the dodder formed "A dense mat almost 



obscuring the clover stems. * * * In some places the clover is 

 killed." 



These extracts indicate how active the dodder may become 

 when once it gains a foothold in the clover field. One field of 

 0v 'erten acres not more than three miles from the Experiment 

 Station was left uncut, because so completely overrun by* the dod- 

 der, and suggests that the seed of the parasite was sown as foul 

 stuff along with the clover seed. While nearly the same shape as 

 the clover, the dodder seed is not more than one fourth as broad 

 or long and should be easily separated by an ordinary fanning 

 mi11 wit h properly adjusted sieves. It is not unlikely that, when 

 the dodder is once upon a farm, it gets distributed in the manure. 

 This species of dodder is one of the most delicate and beautiful 

 of the genus, the slender stems being almost hair-like in their fine- 

 ness and the flowers taking on in some cases a rose pink as delicate 

 as that of the trailing arbutus. The extreme attractiveness of the 

 farming tint of the small clusters of tiny blossoms is brought out 

 as met with upon the stems and leaves of the common wild car- 

 rot {Dauais Carota L.). The accompanying engraving shows 

 tlC inf ested wild carrot plant, and emphasizes the fact that the 

 P ec 'es is not confined to the clovers. It sometimes -rows upon 



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