In most flowers, the very center is the pistil, the plant’s female reproductive part. Around the pistil you’ll usually see the fuzzy or yellow pollen-making stamens, so “the center” is really a small cluster of working parts. On daisies and sunflowers, what looks like one center is actually many tiny flowers packed together. And whichever kind of flower you’re looking at, the center is where the next generation begins, because it’s the part that turns into fruit and seeds.
The Pistil Sits at the Heart of Most Flowers
The pistil usually stands in the middle of the flower and has three sections: the stigma, the style, and the ovary.1University of Illinois Extension. Great Plant Escape – Plant parts The stigma is the tip at the top, often sticky or feathery, and it’s where pollen lands. The style is the stalk that connects the stigma down to the ovary. The ovary is the swollen base that holds the ovules, the tiny structures that become seeds.
To find it on a real flower, look for the single thicker stalk standing straight up in the very middle of a lily or tulip. Its tip is often three-lobed, sticky, or a different color from the stamens around it. On a tulip, the pistil is a stout green column with a three-part top. If you slice the swollen base lengthwise, you can see tiny pale ovules inside.
The full set of female parts is called the gynoecium.2Master Gardeners of Northern Virginia. Gynoecium, Carpel, Pistil It is built from one or more units called carpels.3PubMed. Inside the gynoecium: at the carpel margin A flower with one pistil may still be made of several fused carpels, which is why some fruits split into sections. The gynoecium is the innermost ring of the flower, with every other part arranged around it.4Master Gardeners of Northern Virginia. Gynoecium, Carpel, Pistil “Pistil” is the everyday garden and school term, so for homework it is almost always the expected answer.
Not every flower has a single pistil in the middle, though. Buttercups and magnolias have many small pistils packed on a raised center that looks like a little cone or knob. Squash and cucumber plants separate the sexes: male flowers have only stamens, and female flowers have a pistil. If you find no pistil in a squash flower, you haven’t misread it. Check whether it’s a male flower, which usually sits on a thin stalk with no swelling beneath it. Female squash flowers are easy to recognize because a miniature squash, the ovary, is already visible behind the petals.
The Stamens That Ring the Center
The yellow, dusty parts around the middle are stamens. Stamens are often called the male reproductive structure.5Gardening Solutions, University of Florida IFAS Extension. Parts of a Flower Each stamen is a thin stalk tipped with an anther, the small pod that releases pollen. So the yellow powder that rubs off on your nose or clothes comes from the anthers, not the pistil.
Pollen is a fine powder made of microscopic grains, each carrying the plant’s male genetic material. An anther usually splits open when ripe, and a bud’s anthers are often closed and release nothing until the flower opens. Some flowers shed pollen onto any visitor that brushes past, while others hold it so loosely that wind carries it away. Pollen only works when it reaches the stigma of a compatible flower. Pollen on your clothes has done nothing, but pollen on a bee that visits a second flower may pollinate it.
To tell stamens from the pistil at a glance, count them. Stamens usually come in a ring of several, while the pistil stands alone or in a small central group. Stamens are often thinner than the pistil and either taller or shorter. Lilies show both clearly, so they’re a good flower to practice on. Florists often remove lily stamens because lily pollen stains fabric and tabletops.
Some plants move their stamens toward the middle. In one meadow geranium, the stamens move in groups toward the flower’s center on its first day of bloom.6PubMed Central. Pollination adaptations of group-by-group stamen movement in a meadow plant with temporal floral closure The center is where insects stop for pollen and nectar, so stamens there shed more pollen onto visitors.7PubMed Central. Pollination adaptations of group-by-group stamen movement in a meadow plant with temporal floral closure8Wikipedia. Column (botany)
What Holds the Center Together
The receptacle is the part of the flower stalk where all the flower’s parts are attached.9Biodiversity Counts Curriculum Collection. Parts of a Flower It houses the ovary and other reproductive parts.10Carolina Knowledge Center. Flower Anatomy – Carolina Knowledge Center In bud, these parts are usually protected by the sepals, the small green leaves wrapped around the outside.11Carolina Knowledge Center. Flower Anatomy – Carolina Knowledge Center
On a real bloom, sepals are usually the small green leaf-like pieces right under the petals, and together they’re called the calyx. On a rose, they’re the green points curling out from under the bloom, and they stay attached as the flower grows. They don’t always stay green: on some flowers, such as tulips, they look just like petals. The receptacle is usually hidden behind the petals. Pull the petals off a daisy or a rose and you’ll see the base they all grew from.
Where the ovary sits, above or below the point where the petals attach, is a key feature used to identify flower species.12Tree Guide UK. Flower Ovary Position That’s because some flowers developed a cup-shaped extension of the receptacle that encloses and protects the ovary.13Tree Guide UK. Flower Ovary Position So in some flowers you see the ovary inside the petals, and in others it’s a bump below them on the stem.
You can check this yourself by looking just below the petals for a swelling on the stalk. A lily or tulip has its ovary inside the flower, above the petals. An apple blossom or daffodil has its ovary below the petals, which explains why some fruits carry dried flower remains on the end.
Botanists call an ovary above the petals’ attachment point superior, and one below inferior. An inferior ovary tends to mean the petals and other parts remain at the top of the developing fruit. Some flowers fall in between, with the ovary partly sunk into the cup, so a quick look doesn’t always give a clear answer.
Why Daisies, Daffodils, and Orchids Look Different
Daisies and sunflowers are flower heads made of many small flowers, not one bloom. The center flowers, called disk florets, have petals fused into a tiny tube.14Wikipedia. Pseudanthium – Wikipedia
You can see this on a sunflower. The outer rays are flowers with one big petal each. The center florets open in rings from the outside in, and if you look closely you’ll see tiny tubes with pollen poking out. Each speck in the middle is its own flower with its own pistil, and each fertilized floret becomes one sunflower seed.
The long white “petals” of a daisy are called ray florets, and each one is a small flower with a single strap-shaped petal. In many daisy-type plants they lack functioning parts and serve mainly as a showy border that draws visitors. The green leaf-like bracts under the head look like sepals, but they protect the whole cluster, not a single bloom.
Daffodils and orchids add their own center structures. The trumpet of a daffodil is called the corona, and it grows from tissue between the petals and the stamens.15PubMed Central. The corona of the daffodil Narcissus bulbocodium shares stamen-like identity and is distinct from the orthodox floral whorls Its genes behave more like those of stamens than petals, so it’s a separate add-on, not a petal.16PubMed Central. The corona of the daffodil Narcissus bulbocodium shares stamen-like identity and is distinct from the orthodox floral whorls A daffodil has six petal-like parts around the outside, with the trumpet in front of them, so a first glance misleads. The pistil and stamens are deeper inside, and you have to look down into the trumpet to see them. Short cups and long trumpets are both the corona, a decorative structure around the center. In orchids the center is the column, where male and female parts have merged into one organ.17Wikipedia. Column (botany)
Why Bees and Other Visitors Head for the Middle
Many flowers have a “bullseye” that absorbs ultraviolet light in the center while the outer petals reflect it.18PubMed Central. UV bullseye contrast of Hemerocallis flowers attracts hawkmoths but not swallowtail butterflies Bees can see this contrast, even though people can’t.19PubMed Central. From a bee’s eye: Effects of UV bullseye size on reproductive success in a dioecious vine Herpetospermum pedunculosum (Cucurbitaceae) Yet in one wild test, removing or reversing the pattern didn’t change how often pollinators visited or found the center.20Functional Ecology. Dissecting pollinator responses to a ubiquitous ultraviolet floral pattern in the wild So the bullseye seems to help some visitors, not all, and it isn’t the only cue.
A nectar guide is any pattern of lines, spots, or darker color that points toward the center, where nectar or pollen is found. Some are visible to people, such as the stripes on a pansy or the dark throat of a foxglove. Others show up only in ultraviolet light. A guide shortens the time a visitor spends searching, so it can visit more flowers in a day and carry more pollen between them.
In one flower, insects circle the center to sip nectar, repeatedly brushing the anthers and stigma with their bodies.21PubMed Central. The Functional Dilemma of Nectar Mimic Staminodes in Parnassia wightiana (Celastraceae): Attracting Pollinators and Florivorous Beetles Hawkmoths were drawn to the UV bullseye on daylilies, while swallowtail butterflies were not.22PubMed Central. UV bullseye contrast of Hemerocallis flowers attracts hawkmoths but not swallowtail butterflies The bee orchid takes another route, with a center that looks like a bee to lure male bees.23Martha Stewart. 10 Flowers and Plants That Look Exactly Like Animals
Nectar is a sugary liquid made by glands, often deep in the flower, so a visitor has to reach in past the anthers and stigma to get it. Pollen is a reward too: bees collect it as food for their young. With the reward in the middle, the visitor’s body brushes both the male and female parts on the way in and out.
You can watch this in your garden. Pick a sunny mid-morning, when activity is highest, and watch a bee land and move straight to the middle. Look for pollen collecting on its legs or belly. Flowers like black-eyed Susans have darker, contrasting centers that hint at guides you can see.
What the Center Becomes After the Petals Fall
After fertilization, the ovary usually develops into the fruit, and the ovules inside become seeds.24Biology. Development of Fruit and Fruit Types Fruits that come from other parts, like the receptacle in strawberries or the cup around the ovary in apples and pears, are called accessory fruits.25Biology. Development of Fruit and Fruit Types
On a strawberry, the tiny seed-like dots are the true fruits, each from a pollinated pistil.26University of Minnesota. What Is the Center of a Flower Called? More pollinated pistils means more dots and a bigger strawberry.27University of Minnesota. What Is the Center of a Flower Called? Unpollinated sections of the center don’t swell, so berries come out small or misshapen. Few bee visits during cold or rainy bloom weather is a common cause, and brushing flower centers with a small paintbrush can help garden plants.
In an apple, the core holds the seeds and is the true fruit, while the flesh you eat comes from the cup around the ovary. Cut an apple across the middle and the star-shaped core is the ovary wall, with seeds in each section. A peach or cherry is closer to the usual pattern, where the ovary wall becomes the fruit and the pit holds the seed.
Leftover flower parts show which part became the fruit. The dry tuft on the bottom of an apple is the remains of the flower, a pea pod’s tip shows where the style was, and a tomato’s green cap is the old sepals.
Some centers are valuable before they ever fruit. Saffron is the dried red stigmas from the center of the saffron crocus.28University of Vermont. Harvesting Saffron Flowers Growers separate the red stigmas, yellow stamens, and purple petals by hand before drying.29University of Vermont. Harvesting Saffron Flowers Each flower yields only a few threads, which helps explain saffron’s high price.