Ovule—after fertilisation the ovule develops into the seed. The egg and the polar nuclei
are fertilised by the two male nuclei.
Ovary—develops into a fruit when stimulated by fertilisation, or when auxin or other
growth hormones are artificially applied, or in apomixes—the production of seed
without a male gamete.
Polar Nuclei—the two nuclei near the centre, they develop into the seed endosperm.
Egg Nuclei—develop into the seed embryo.
Integuments—develop into the seed coat, or “testa”.
Figure 1. Schematised longisection of a flowerThe organisation of the male (staminate) and female (pistillate or ovule-producing)
flower parts is different for every plant species, but there are two main types of plants:
Monoecious plants have both male and female flowers on the same plant, eg maize,
cucumber, beans and virtually all other food crops.
Dioecious plants have separate male and female flowers, and on different plants, eg
asparagus, date palms and most papaya varieties, but very few other food crops.
Flowers are either self-pollinated (autogamy, producing other “selfer” plants) if pollen
is transferred to it from any flower of the same plant, or cross-pollinated (heterogamy,
producing other “out crosser” or “out breeder” plants) if the pollen comes from a flower
on a different plant.