PLANTAGINACEAE 



323 



easily shaken by the wind. These flowers seem to be exclusively anemophilous, for 

 Delpino never saw them visited by insects. 



(2) Plants with shorter scapes, which also seem to be almost exclusively 

 anemophilous, for Delpino only once saw a Halictus collecting pollen on the 

 inflorescences. 



(3) A dwarf mountain form, with short spikes and stamens. Delpino observed 

 numerous bees collecting pollen, while the Halictus mentioned above could only 

 collect a small amount, most of it falling 

 to the ground. 



Delpino concluded from this last 

 observation that the structure of the 

 flowers is unsuited for pollen-collecting 

 bees. Hermann Miiller rightly observes, 

 however, that Delpino has possibly taken 

 for granted certain adaptations in the 

 third form (on which he saw the honey- 

 bee collecting pollen) which are not 

 actually present, simply because of the 

 abundant pollen collected by the honey- 

 bee. This, however, results from this 

 bee's habit of smearing the pollen with 

 nectar. 



Gynomonoeciously or gynodioeci- 

 ously distributed female flowers occur 

 now and then in addition to the 

 hermaphrodite ones. Schulz says that 

 they are usually 20-25 %; ^.nd some- 

 times even 50 %. The flowers of purely 

 female stocks have either yellow anthers with reduced pollen, or no anthers at all. 

 They are more fertile than the hermaphrodite flowers, and only appear (according 

 to Ludwig) towards the end of the flowering season. Different zones of flowers can 

 be recognized on the spikes of gynomonoecious stocks, one bearing purely female 

 flowers, another hermaphrodite ones, and the third of intermediate character with 

 occasional reduced stamens. 



Visitors. — Hermann Miiller in Westphalia, and myself in Schleswig-Holstein, 

 saw the honey-bee as a pollinator. Hermann Miiller gives the following account 

 (with which my own observations agree) of the way in which it visits the flowers 

 (op. cit., pp. 505-6).— 



' The honey-bee flies buzzing to a spike, and while it hovers in the air it spits 

 a little honey on the exserted anthers. Then, still hovering and buzzing, it brushes 

 pollen with the tarsal brushes of its forefeet off' the anther, the tone of its humming 

 becoming suddenly higher ; in the same instant one sees a cloud of pollen rise from 

 the shaken anthers. After placing the pollen on its hindlegs the bee repeats the 

 operation on the same or other spikes, or if it is tired it alights on the spike and 

 creeps upward. Since the scattered pollen in part reaches the stigmas of the same or 

 neighbouring plants, we have here anemophilous flowers fertilized also by insects.' 



In windy weather the honey-bee behaves quite differently when collecting pollen. 



Y 2 



Fig. 345. Planlago lanaolala, L. (after Herm. 

 Miiller). (i) Flower in the first (female) sta^e ; petals 

 and stamens still enclosed in the bud. (2) Do., after 

 removal of the calyx. (3) An anther from the same 

 flower. (4) Flower in the second (male) stage. (5) The 

 cohering lower sepals. (6) A lateral sepal. 



