PARASITIC PLANTS 341 



shrubs, or even trees, and produce sucking organs on their stems 

 that come in contact with their host. 



These are all smooth plants, with globular clusters of yellowish- 

 pink flowers, the calyx being of the same colour as the corolla. The 

 former is deeply divided into four or five parts, and the corolla has 

 four or five spreading lobes with as many scales inside its broad 

 tube. The ovary has two distinct styles, and the fruit is a globular 

 capsule. The following summary of distingmshing features will 

 enable the reader to identify the British species of the genus : — 



1. The Greater Dodder {Cuscuta europcea). — A plant of a greenish 

 yellow colour, generally more or less tinged with red, with flowers 

 in sessile, globular clusters nearly half an inch in diameter, each 

 individual flower being about a tenth of an inch. This species is 

 not abundant. It may be met with in hop-fields, and is also 

 parasitic on nettles, various shrubs, and trees, including the elder 

 and the ash. 



2. The Flax Dodder (C. Epilinum). — Very much like C. europcea , 

 but the flowers are fewer in number, larger, and more fleshy. The 

 calyx is nearly as long as the corolla, with sharply-pointed segments ; 

 and the corolla tube is always globular. This species is not indi- 

 genous, but is sometimes met with in flax-fields. 



3. The Lesser Dodder {C. Epithymum). — A more slender plant, 

 with thread-like stems, and flowers in small, compact, globular 

 heads, with red calyx and cylindiical corolla. This species occurs 

 principally on sunny heaths, where it is parasitic on shrubby 

 plants, such as thyme and ling. It is much more common than 

 the foregoing. 



4. The Clover Dodder {C, Trifolii). — ^Very much like the Lesser 

 Dodder, of which it is sometimes regarded as a variety. Its calyx 

 is of a very pale colour, and is almost as long as the tube of the 

 corolla, which is cyhndrical in form. It is rare, but sometimes 

 appears in undesirable numbers in clover fields. 



All the species produce their flow^ers in August and September, 

 but C. eurojma may often be seen in bloom very early in July. 



The seeds of the Dodder fall from the opened capsules dming 

 late summer and early autumn, ahghting on the soil, or on the 

 decomposing fohage that covers the groimd, or on the rough barks 

 of the tree that served as a host for the parasitic plant. The seeds 

 of many other plants fall about the same time, but those of the 

 Dodder do not begin to germinate until about a month later than 

 the majority of these, in the following season, and consequently 



