The pistil consists of a single carpel with its ovary, style, stigma and solitary ovule or twin ovules.
Each carpel terminates in a peltate head.
The ANGIOSFERMS, which are much the larger class, derive their name from the fact that the carpel or carpels form a closed chamber, the ovary, in which the ovules are developedassociated with this is the development of a receptive or stigmatic surface on which the pollen grain is deposited.
In the first-mentioned case the terms carpel and pistil are synonymous.
Each carpel has its own ovary, style (when present), and stigma, and may be regarded as formed by a folded leaf, the upper surface of which is turned inwards towards the axis, and the lower outwards, while from its margins are developed one or more ovules.
This is seen in cases where the margins of the carpel do not unite, but remain separate, and consequently two placentas are formed in place of one.
When the pistil is formed by one carpel the inner margins unite and form usually a common marginal placenta, which may extend FIG.
From the lower part of a carpel are produced several laterally placed ovules, which become bright red or orange on ripening; the bright fleshy seeds, which in some species are as large as a goose's egg, and the tawny spreading carpels produce a pleasing combination of colour in the midst of the long dark-green fronds, which curve gracefully upwards and outwards from the summit of the columnar stem.
As the placenta is formed on each margin of the carpel it is essentially double.
The style proceeds from the summit of the carpel (fig.