THE YOUNG NATURALIST. 



peculiar sucker-like roots called " hau- 

 storia," which not only serve to fasten 

 the parasite to its "host," but they 

 suck up and absorb its juices, for as 

 soon as the dodder has become firmly 

 fixed to its supporting plant, the stem 

 below the attachment withers away 

 and ceases to have any connection 

 with the ground at all, and the dodder 

 then becomes a true parasite, living 

 entirely on its " host," and producing 

 its flowers and seeds at its expense'. 

 It will thus be seen that the parasitical 

 habit has not yet become so confirmed 

 in the dodders as in the . mistletoe, for 

 they are able to germinate and grow 

 for some time in the earth, and only 

 spend a portion of their existence as a 

 parasite. The different species of 

 dodder attach themselves unfailingly 

 to particular plants : thus C. Epilinum 

 is found parasitical only on flax, where 

 it sometimes becomes exceedingly in- 

 jurious to the crops ; C. trifolii grows 

 on clover, spreading centrifugally over 

 considerable patches to the exclusion 

 of everything else ; C. Ejoithymum 

 prefers heath and furze ; whilst C. 

 Europcea affects common nettles. 



The second class of flowering para- 

 sites are those which attack the roots 

 of plants. The best known of these 

 are the broomrapes (Orobanche) , of 

 which about ten species and varieties 

 are recognised as indigenous. These 

 have an entirely different habit to the 

 dodders, being stout, fleshy, scaly 



plants of a uniform dull brown hue 

 and generally unattractive appearance. 

 They sometimes attain considerable 

 size : I have gathered 0. major on 

 broom over two feet high and as thick 

 at the base as a man's thumb. The 

 mature plant possesses no true roots, 

 but the base of the stem becomes 

 enlarged and swollen and firmly ad- 

 herent to the root of the plant on 

 which it grows, and so intimately 

 united with it as to intercept and ab- 

 sorb the juices of its "host." The 

 flowers are numerous and quite as 

 large as those of the white dead-nettle. 

 The seeds germinate in the ground, 

 and the infant rootlets soon find their 

 way to the roots of their " host " and 

 become closely attached to it. If they 

 are unable to reach a suitable nidus 

 they soon shrivel and perish, being 

 unable to extract sufficient supplies 

 from the soil. The Orobanches have 

 a pretty wide range of sustaining plants 

 on which they are able to feed, showing 

 that the parasitic habit has been long 

 acquired by them. They more par- 

 ticularly affect papilionaceous or the 

 pea family of plants, hence their 

 botanic name of Orobanche, from Orob, 

 a vetch, and anche, to strangle, from 

 their devastating effect upon the plants 

 on which they fasten. 



The most common, abundant, and 

 easily discovered of our British para- 

 sites is the toothwort (Lathrea squam- 

 aria), which is frequent in loamy woods 



