Seed-producing plants use sexual reproduction to produce their seeds and are divided into two main groups:
- Angiosperms, the true flowering plants with enclosed ovaries where the seeds are housed in a fruit.
- Gymnosperms, with naked seeds usually housed in cones or cone-like structures.
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| Seed plant reproductive configurations, but many people combine homoecious (self-fertile or perfect flowers) with monoecious since each plant has both male & female flowers or flower parts. |
There are 3 arrangements or configurations of these sexual organs:
1) Dioecious where the male and female structures are housed on separate plants. The main advantage to this arrangement is that cross pollination is forced, so there is more genetic diversity, which allows the plants with the best characteristics to adapt to a changing environment. The disadvantages are that only half of the plants produce seeds and the spread into to new territories is slowed because both male & female plants must be within breeding range.
2) Monoecious where male and female structures are separate, but on the same plant. The advantage is that the male and female structures are close, but pollination still needs to take place and more cross-pollination may occur. Examples include the squash family (Cucurbitaceae) with separate male & female flowers and some grasses like corn (Zea mays) with their male flowers at the top of the plant and the female flowers tucked into leaf notches that become the ears.
3) Homoecious, hermaphroditic or self-fertile where male and female parts are housed in the same structure. For Angiosperms, this would be a "perfect flower." The advantage is that pollination is much more likely, but one disadvantage is that self-fertilization is likely, which causes less genetic diversity. Some hermaphroditic plants have adapted so they cannot fertilize themselves. The vast majority of angiosperm flowers are perfect.
Dioecious derives from Greek meaning two houses, and as you can probably guess, monoecious means one house. Homoecious is self or the same house.
