THE FLOWER 219 
which pollen grains adhere when the stigma is touched by a 
part of an insect on which pollen has been caught. 
Water-pollination. A few species of submerged water plants 
have female flowers that lie on the surface of the water and 
male flowers that become detached, float to 
the female flowers, and deposit pollen on 
the stigmas. A well-known example is the 
common eel grass, J’allisneria (Fig. 217). 
Conspicuous flowers. In typical flowers 
the conspicuous part is the perianth, but in 
many insect-pollinated species the perianth 
is lacking or inconspicuous, while other 
structures are showy and serve for the 
attraction of insects (Figs. 80, 218). 
In Acacia and many others of the bean 
family the perianth is inconspicuous, but a 
large number of flowers with long stamens 
are crowded together into a showy, rounded, 
feathery ball (Figs. 219, 220). 
In Canna the calyx and corolla are rather 
inconspicuous, and the bright-colored part 
of the flower is composed of petal-like ; 
stamens (Fig. 221). Fig. 225. Flower clus- 
In many species the flowers themselves ter of elephant’sear 
are small and inconspicuous but are sur- (Alocasia indica) 
rounded by large, brightly colored, leaflike ‘ne infloresence is in 
bracts (Figs. 81, 222). In the family Ava- the center, the upper 
ceae a large number of small flowers are ae Deine ees 
1e lower bearing numer- 
crowded together on a long stalk. The ous mowers; the wholeis 
whole flower shoot is more or less sur- surrounded bya special- 
rounded by a large white or bright-colored 12° !e@f called a spathe. 
bract called a spathe (Fig. 223). ae) 
In many cases individual flowers are not showy themselves 
but are crowded together in groups which are very conspicu- 
ous. In the family Compositae this condition is carried so far that 
the individual flowers are crowded into heads which superficially 

