598 WEEDS : SPECIAL 



Clover-Dodder {Cuscuta Trifolii Bab.) is a formidable enemy 

 when once established. It is met with chiefly upon red clover 

 and lucerne, and, except for a very short time after germination, 

 the plant has no connection with the soil. The seed which is 

 figured on page 647 gives rise to a white thread-like seedling 

 without leaves of any kind. It is unable to utilise ordinary 

 manurial ingredients of the soil, and unless it meets with a 

 clover plant, it dies in a short time. Should a clover plant be 

 in the immediate neighbourhood, the thin seedling winds round 

 its stem, and at points of contact protrudes roots or haustoria 

 (suckers) which penetrate into it. After making one or two 

 complete ring-like turns round the stem, the dodder extends its 

 growing point, branching at the same time, and coiling itself 

 round its victim in new positions. It spreads from plant to 

 plant outwards in all directions, so that considerable patches 

 become infested by it. 



Its very thin stems resemble a tangled mass of coarse, red- 

 dish-yellow horse hair, and as the plant is without leaves and 

 possesses no chloroplasts, it is unable to make use of the carbon 

 dioxide of the air, and is compelled to depend upon ready-made 

 food obtained from other sources. These it absorbs by means 

 of its roots or suckers from the clover plant, and large crops may 

 be completely destroyed by the parasite. 



Dodder is an annual even when growing upon perennial plants, 

 and produces small white bell-shaped, flowers in compact clusters. 

 The fruit is a two-celled capsule usually containing four seeds, 

 which fall to the ground when ripe, and germinate very late in the 

 following spring. In wet seasons the seeds seem to germinate 

 best. 



It is important that seeds of clovers containing dodder should 

 never be sown. Continental samples often contain this impurity, 

 but it is easily removed by proper sieves, and a guarantee that 

 samples are free from it should be obtained from the seedsman. 

 As soon as it is observed in a field, measures should be taken to 



