Huntington>Conservatory>Plant Lab>Flower> Flower Types by Sexual Variations


Flowers are a group of highly specialized structures used in the sexual reproduction of angiosperms. Every aspect of a flower (appearance, scent, pollen, nectar, etc.) is adapted for efficient pollination to produce seeds.

Flower types according to ovary position and fusion of flower parts:

Superior ovary:

Perianth and stamens attach to receptacle below the ovary

Hypogynous flowers:

One or more pistils, each with a superior ovary;
the bases of the perianth and stamens are separated.

Examples: geranium, carnation.

Perigynous flowers

One or more pistils, each with a superior ovary;
the bases of the perianth and stamens are fused into a cup-like hypanthium.

Example: rose.

Inferior ovary:

Perianth and stamens join on top of the ovary

Epigynous flowwers

A single pistil with an inferior ovary;
perianth and stamens can also fuse with ovary to form hypanthium.

Examples: orchid, apple, fuschia, squash.

Flower types according to sexual variations:

Although the basic structure of a flower has four floral series, specialized variations have evolved for greater efficiency.
bisexual or hermaphrodite

Has both fertile floral series.
always perfect
Has all four floral series.
Examples: hibiscus, cactus, tulip.
INCOMPLETE A perfect flower missing one or more sterile floral series.

Has only one fertile floral series.
Pistillate flowers: with only gynoecium
Staminate flowers: with only androecium

Plant types:

Flowering plants are categorized according to their flower types.


Plants with perfect flowers


Plants with imperfect flowers


Have both male and female flowers on the same plants.
Common with wind-pollinated plants.
Examples: maize, amorphophallus, jackfruit etc..


Male and female flowers on separate plants.
No self-pollination (leading to greater diversity), but requires plants with opposite sexes to be close together.
Examples: tropical pitcher plant, sweet bay, ginkgo, date palm, holly, asparagus, pampas grass etc..

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