11 SCROPHCJLARIACE^ 319 



Melampyrum (Cow-wheat) 



Flowers unsymmetrical, with nectar secreted by a gland 

 at one side of the ovary. Semi-parasitic like Bartsia and 

 Rhinanthus. The suckers resemble those of Rhinan- 

 thus, with which it also agrees in the general arrange- 

 ment of the flower. The conspicuousness of the flowers 

 is in some species enhanced by the presence of coloured 

 bracts. There are four British species. Two have 

 yellow flowers ; one, M. pratense, with the upper bracts 

 toothed at the base, while in the other, M. sylvaticum, 

 they are entire. . The other two species have yellow 

 flowers variegated with purple ; one, M. cristatum, has 

 the bracts finely toothed, while in M. arvense they 

 have long slender teeth. 



M. pratense. — The corolla-tube has a length of 14- 

 15 mm., but as humble bees can press their head a short 

 way into the entrance a proboscis 10-11 mm. long is 

 sufficient to reach the nectar. This, however, excludes 

 the hive bee and Bombus terrestris, which often bite 

 through the corolla and thus rob the flower of its nectar. 

 The flowers are horizontal, and the stigma hangs over 

 the entrance. Inside the tube the anthers touch at 

 their edges and thus form a pollen-box. At their lower 

 ends are projecting teeth, which are pressed on one side 

 by the bee, thus unlocking the box and setting free the 

 pollen. In the absence of insects the filaments gradually 

 become flaccid, in consequence of which the anthers 

 separate, and as in the meanwhile the style has bent 

 downwards, some of the pollen 

 generally drops on the stigma, ft D fl 



In most flowers the secretion of "^ w • 



nectar ceases when the flower ^ ^ 



fades. Melampyrum, however, pig. 208.— i, seed of Meiam- 



•^ •' T , 1 pyrum ; 2, chrysalis of 



IS an exception, and the reason Formica f mm. 

 is interesting. The result of the 



continued secretion of nectar is that the plants are 

 visited by ants [Formica fusca). The seeds of Melampy- 

 rum (Fig. 208) curiously mimic the chrysalis of a common 



