Any part of the flower may secrete nectar, as the bracts, sepals, petals, stamens, and pistils; but most frequently it is secreted near the base of the styles. Its quantity varies from an almost imperceptible layer to several drops or even a spoonful. In the tropical orchid coryanthes there collects in the hollow lip more than an ounce avoirdupois.
The bees, especially the honeybees, far surpass all other insects in importance as pollinators, for they are almost entirely dependent upon a floral diet, both for food for themselves and their offspring. The honeybee is on the wing very early in the spring, and continues to fly until late in the fall. Its great numbers, its general size and shape, the special construction of its tongue and legs, all together make it especially well adapted for collecting and carrying pollen.
Nectar is secreted by flowers in order to attract the bees. After a bee has found nectar in one flower it will be very likely to examine others of a similar kind or appearance. If the flowers were all green, like the leaves of the plant, the bees would have much more trouble in hunting them up than they now do, because contrasting colors, such as the white and red of the clovers, make them conspicuous.
It is significant that so many of the flowers have a form of construction and depth of flower tube that would indicate that it had adapted itself to the bee. While, of course, there are many exceptions, it appears that nature caters more to the bee than to any other insect. Just see how she makes a convenient doorstep or a flower tube of Just the right size and shape, so that the bee can get the nectar which it has to offer! Chesire has pointed out that so intimate and so perfect is the relation between the flowers and the honeybees that there would be no advantage in breeding larger bees or of changing their general structure, because to do so would necessitate changing practically the whole of the floral kingdom. While it undoubtedly would be an advantage to breed bees with longer tongues,