LEGUMINOS^: 



155 



Europe, where some of the species have trifoliate leaves ; 

 ours are all single-leaved. One of our species, G. anglica, 

 is spinous. Of the other two, G. pilosa has the corolla 

 and pods hairy ; the other, G. tinctoria, glabrous. The 

 Genistas are pollen flowers, i.e. honey less. 



G. tinctoria. — The ten anthers ^ lie in two distinct 

 rows. While the flower is still in the bud, the four upper 

 anthers of the outer row are already on the point of 

 opening, while those of the inner circle have not nearly 

 reached their full size. These four anthers now open 

 and shed their pollen into the space at the apex of the 

 keel, after which they shrivel up. The fifth, although 

 it has attained its full 

 size, remains closed. The 

 next process is that this 

 anther and those of the 

 second row also open, 

 and the pollen occupies 

 the end of the keel be- 

 tween the anthers and 

 the stigma, as in Lotus. 

 While, however, in Lotus, 

 when the insect leaves the 



Fig. 103. 



Figs. 101-103. — Flower of Genista tinctoria. 

 Fig. 101. — Unopened. 

 Fig. 102.— Opened. 



flower and the pressure is f^. los.— After being visUea. 



,1 J J.T. 1 1 std, standard : w, wing ; k, Iteel ; m, 



thus removed, the keel projection on iceei. 

 resumes its position and 



the stamens and pistil are again protected, in G. tinc- 

 toria, on the contrary, the flower opens once for all. The 

 keel is at first nearly parallel to the standard (Fig. 101). 

 This position is, however, one of tension ; the keel is 

 retained in it by the union of its upper margins, which 

 enclose and retain the curved pistil, which presses against 

 them like a spring. The sides of the keel have near the 

 base a projecting lobe (Fig. 103, m), which locks with one 

 at the corresponding part of the wing. When an insect, 

 alighting on the flower, presses open the keel in search 

 of pollen, as soon as the curved end of the pistil is set 

 free it springs up with a jerk, the keel, on the contrary^ 



^ Avebury (Lubbock), British Wild Flowers. 



