GAMOPETAL.E 159 



The other types consist of plants that live in or on 

 decaying organic substances, and derive their nutri- 

 ment from them. Such are Yellow Bird's Nest, 

 Bird's Nest Orchid, Coral Root, or Saprophytes, the 

 first possessing mycorhiza, and in this way symbiotic. 



In the case of parasites, such as the Broom Rapes, 

 the nutriment is derived from the host by the aid of 

 suckers or haustoria, which connect the roots of the 

 parasite with those of the host. These suckers are 

 roots adapted to the special mode of nutrition and 

 parasitism. They are organically united with the 

 tissues of the host, and are equally subject to changes 

 that it may undergo. Some are parasitic upon 

 roots, as here, others on stems, as in the case of 

 Dodder {ante). 



In the Broom Rape group the embryo does not 

 possess cotyledons, and there is no radicle and no 

 epicotyl. The end representing the shoot remains in 

 the seed. The opposite end takes a spiral course when 

 germinating, and if not meeting with the roots of the 

 host dies, as in the case of Dodder. The developing 

 filament or rootlet adheres to the host, increases in 

 thickness, and dies down above, whilst the lower part 

 sends peg-like structures into the host, living on its 

 sap. A bud is developed, which later becomes a 

 stem, with rootlets, some of which may derive nutri- 

 ment directly from the soil. 



There is some meaning in the name Orobanche, 

 in that it denotes " strangle vetch," the plant living 

 on vetches and withdrawing their substance. The 



