The Flower. The flower consists of several parts.
The calyx, or flower cup, forms the external integument which protects the bud before it expands : it consists of several parts, called sepales, resembling small leaves, both in form and colour. These sepales are, in general, more or less soldered together ; sometimes so completely as to form a cup apparently of one piece.
Above and within the calyx rises the corolla, which is the coloured part of the flower. It is composed of several petals, either separate or cohering, so as to form a corolla of one single piece : in the latter case, the flower is called monopetalous. When the petals first burst from the calyx, and expand in all their beauty, they still serve to protect the central parts of the flower. They are at first curved inwards, forming a concavity around the delicate organs which occupy the centre. This not only shelters them from external injury, but reflects the sun's rays upon them, like a concave mirror; thus rearing them, as it were, in a hot-house. When these parts are full grown, the artificial heat being no longer necessary, and the admission of light and air being not only safe but advantageous, the petals expand ; leaving the internal organs exposed to the free agency of these elements.
At the base of the petals is generally situated an organ, called the nectary. This is the store whence the bee derives honey.
The most important parts of the flower are those organs which occupy the centre. It is here that the seed which is to propagate the plant is lodged, in a vessel called the ovary, or seed-vessel. From its summit rises a little threadlike stalk, culled a style ; which, at its extremity, supports a small, spongy substance, denominated the stigma. These three parts form a whole, which bears the name of carpel.
Immediately surrounding the pistils are situated the stamens; each of which consists of a slender filament, supporting a little bag, or case, called an anther, filled with pollen, which is a species of dust or powder. The anthers, when ripe, burst; and, being more elevated than the stigma, shed their pollen upon it; without which no seed can be perfected.
In some vegetables the stamens are in one flower and the pistils in another ; in others, the stamens and pistils are upon separate plants. In these cases the pollen is conveyed from the one to the other by means of the wind, or by winged insects, which, in penetrating, by means of their long and pliant proboscis, within the recesses of the corolla, in order to obtain the nectar, cover their downy wings with the pollen. This unheeded burden they convey to the next flower on which they alight; and in working their way to the nectary, it is rubbed off and falls on the stigma. Every insect, however ephemeral, every weed, however insignificant, has its part assigned in the great system of the universe.
In Persia, very few of the palm and date trees, under cultivation, have stamens, those having pistils being preferred, as alone yielding fruit. In the season of flowering, the peasants gather branches of the wild palm trees, whose blossoms contain stamens, and spread them over those which are cultivated, so that the pollen comes in contact with the pistils, and fertilizes the flower.
There were two remarkable palm-trees in Italy. The one, situated at Otranto, had no stamens; the other, at Brindisi, which is about forty miles distant, had no pistils; consequently, neither of those trees bore seed. But when, after the growth of many years, they not only rose superior to all the trees of the neighbouring forests, but overtopped all the buildings which intervened, the pollen of the palm-tree at Brindisi was wafted by the wind to the pistils of that of Otranto; and, to the astonishment of every one, the latter bore fruit.