178 BRITISH PLANTS 
As a matter of fact, in this order the flowers actually 
provide against the failure of cross-pollination. The 
stigmas after a while, whether pollinated or not, curl 
over their tips, and explore the withered anthers or style. 
for any stray pollen that may happen to be still clinging 
to them, thus insuring fertilization for every ovule. 
The subject of pollination is extremely wide and varied, 
but we have not the space to describe in detail the many 
curious devices found in flowers to prevent self-fertiliza- 
tion, nor to give an account of the wonderful adaptations 
for pollination by long-tongued insects. In some cases 
specialization has been carried to such a length that 
fertilization is dependent upon the visit of one kind of 
insect only, so that, in its absence, no seed is formed. 
The limits, then, of the plant and the insect are coter- 
minous. In other cases the insect and the flower have 
so adapted their habits to each other’s needs that the 
life-history of the one is not completed without the aid 
of the other. We do not say that this is advantageous 
to the flower. It isnot. The disappearance of the insect 
means the extermination of the flower. 
Inflorescences and Pollination. 
Flowers may be solitary, or more usually arranged in 
groups on special stems. An inflorescence is a shoot 
devoted entirely to the production of flowers. Most 
solitary flowers are large and conspicuous, and insect- 
pollinated—e.g., poppy, water-lily, wood-anemone. 
I. Axis of Inflorescence Elongated : 
1. Raceme, flowers stalked. 
2. Panicle, a branched raceme. 
3. Spike, flowers sessile. 
(a) Catkin, pendulous, flowers unisexual. @ 
(b) Spadix, axis fleshy, flowers unisexual and 
surrounded by a spathe. 
4. Cyme, flowers usually stalked, axis terminating 
in a flower. 
II. Axis of Inflorescence Short : 
5. Head or capitulum, flowers sessile. 
6. Umbel, flowers stalked. 
