5o6 



BOTANY OF THE LIVING PLANT 



illustrate their very simple floral structure. In the large shrubby Goat-Willow 

 {Sali.x caprea. L.) the flowers appear grouped to form the well-known Catkins, 

 or " Palms." These are of two sorts, distributed on different plants (dioecious) 



Fig. 40S. 

 Catkins of the Willow, a, male ; &, female, {.\fter Figuier.) 



(Fig. 408). The Diale catkins appear bri.ght yellow when in bloom, from 

 their projecting stamens ; the female cat/ii)!s are more slender, and of oUve- 

 green colour. In each case the catkin is a spike. Its main axis bears 



darkly-coloured bracts, and in the axil of 

 each of these is a single ^'cry simply- 

 constructed flower. 



The ttiale flower (Fig. 409, a) consists of 

 two stamens, each with a long filament, 

 which bears the anther, with stick)', not 

 dustv pollen. There is no perianth, nor 

 gynoecium ; but on the side next the 

 stem is a nectary, which secretes honey 

 freely at flowering (Fig. 410, A, d). Other 

 species may have three, four, or more 

 stamens, but no other floral parts (Fig. 

 410, C). The female flower (Fig. 409, b) 

 IS also axillary. It consists only of a 

 gynoecium o[ two carpels joined by then- 

 margins to form a unilocular, superior 

 ovary with two-Iobed stigma. The ovules are numerous, and the placenta- 

 tion parietal. A honey-gland is present here also between the flower and 

 the main axis (Fig. 411, A). 



PoUiiiatiou. The flowers of both catkins are \-isited freely by insects, both 

 bees and moths, for honey or for pollen. Self-pollination is obviously im- 

 possible, for the plants are dioecious ; but crossing follows as a natural 



Flowers of Willow {SuUx alba), a, male ; 

 b, female : in each case the subtending bract 

 is also showTi. (After Figtiier.) 



