Summary
Reproductive structures of angiosperms containing sepals, petals, stamens and carpels.
In depth
Sepals protect the bud, petals attract pollinators; stamens (anther, filament) make pollen; carpels (stigma, style, ovary) contain ovules. Wind-pollinated flowers are small with feathery stigmas; insect-pollinated ones are colourful and scented.
Perfect flowers have both stamens and carpels; imperfect flowers have only one. Flower structure is adapted to pollinators: tubular red flowers suit hummingbirds, and flat landing platforms suit bees.
Remember: the ovary becomes the fruit and ovules become seeds.
Flowers are reproductive shoots that evolved around 140 million years ago or earlier. Complete flowers have all four whorls, incomplete lack some, and perfect flowers have both stamens and carpels. Wind-pollinated flowers (grasses) are small with feathery stigmas and lots of pollen, while insect-pollinated flowers have scent, nectar and bright colours, including ultraviolet patterns visible to bees.
Inflorescences such as the daisy head are clusters acting as one large flower. Flower diversity results from coevolution with pollinators: bats, birds, moths and bees each favour particular shapes and colours (red tubular flowers for hummingbirds). Floral formula and diagrams describe structure for identification.
Example: the rafflesia flower smells of rotting meat to attract flies, and is the largest single flower.
Frequently asked questions
What is Flowers?
Reproductive structures of angiosperms containing sepals, petals, stamens and carpels.
Which area of biology covers Flowers, and how advanced is it?
Flowers is one of the 56 topics in Plant Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Floral Development ABC Model, Plant Kingdom, Pollination.
Can you give an example of Flowers?
Grasses use wind pollination.
What should I learn before Flowers?
Flowers is a Beginner topic, so no earlier topic is required. Other Beginner topics in Plant Biology that pair well with it include Plant Kingdom, Photosynthesis, Chlorophyll.
What topics are related to Flowers?
The closest topics to Flowers are Floral Development ABC Model, Plant Kingdom, Pollination, Monocots vs Dicots. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Flowers?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Flowers. To practise the whole of Plant Biology, use the Plant Biology quiz.
How is Flowers different from Floral Development ABC Model?
Flowers: Reproductive structures of angiosperms containing sepals, petals, stamens and carpels. Floral Development ABC Model: Combinations of A, B and C class genes specify sepals, petals, stamens and carpels. Read both side by side and note what each one explains.
How should I study Flowers step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Floral Development ABC Model and explain the difference aloud. Finally, take the Plant Biology quiz and come back to this page for any question you miss.