22, we recognize four distinct whorls of leaves: an outer whorl, the calyx of sepals; within it, another whorl, the parts alternating with those of the outer whorl, the corolla of petals; next a whorl of parts alternating with the parts of the corolla, the androecium of stamens; and in the centre the gynoecium of carpels.
The gynoecium or pistil is the central portion of the flower, terminating the floral axis.
The androecium and gynoecium are not present in all flowers.
A flower then normally consists of the four series of leaves - calyx, corolla, androecium and gynoecium - and when these are all present the flower is complete.
In this case it is the gynoecium which has an additional number of parts.
The pistil or gynoecium occupies the centre or apex of the flower, and is surrounded by the stamens and floral envelopes when these are present.
- Gynoecium of the Flowerde-Luce (Iris), consisting of an inferior ovary (o) and a style which divides into three petaloid segments (s), each bearing a stigma (st).
It remains to be seen if the ovuliferous cone in the centre of the flower represents simply a functionless gynoecium, as in Welwitschia and abnormal cones of certain Coniferae, or if the flowers were hermaphrodite, with both male and female organs fully developed.
We have a combination in the same flower of stalked ovules, the structure of which has already been described, and interseminal scales constituting a complex gynoecium, which exhibits in certain features an approach to the angiospermous type, and differs in structure from other Gymnosperm flowers, associated with male organs constructed on a plan almost identical with that.
This fact suggests the possibility that the flowers described by Mr Wieland, in which the male organs are mature and the gynoecium is composed of very short and immature ovuliferous stalks and interseminal scales, are not essentially distinct from those which have lost the staminate leaves FIG.
We cannot decide at present whether the gynoecium in a flower, such as that represented in fig.