The parts of a flower which are involved in reproduction.

Gorgeous assorted flowers in terracotta patio pots.

When dealing with the parts of a flower, we must keep in mind that every flower, no matter how beautiful or ugly, simple or complicated, has only one purpose: to make itself utterly irresistible to whatever type of pollinator it needs (if it needs one at all) to carry on the genetic code which makes it a flower and not a mouse. Flowers are used by plants for sexual reproduction. 

We're all used to the typical flowers we see around us every day,  but we are in for a few surprises if we look deeper.   There are two types of flowers: typical (perfect) and non-typical (imperfect) - these are  the basic types we need here.

And then, there are the Fibonacci Numbers, of course, and they don't just stop at flowers.

The Female Parts of a Flower.

A typical (perfect) flower has a female part: the Pistil (also called the Carpel). This is made up of the stigma, the style and the ovary. The ovary contains the ovule (or ovules) where fertilization occurs. The stigma is where the pollen lands. The pollen then grows a tube which moves downwards through the style until it reaches the ovary. (In the maize plant, the pollen tube can grow to 12 inches!)

The Male Parts of a flower.

It also has male parts which are made up of the Stamen which consists of the anther (which has the pollen) and the filament (the little stalk). This is easily seen in a lily. 

Flowers also have nectaries where the nectar is produced and nectar guides or lines which may be in the ultraviolet so that only insects can see them; but many are visible to humans.  Other guides may be oils, fragrance,  resins or waxes.

The pollinators are called Vectors and include birds, bees, butterflies, moths and many other types of insects.

The Oriental Lily will leave a stain on your finger (from the pollen) if you touch the anther and this is poisonous to cats. So not a good idea in the garden if you have cats. We will just have to keep buying them as cut flowers, or keep them in a pot out of a cat's reach. However, there is a new Oriental Lily which will not leave a stain, but it does not have much fragrance. It's called 'China Girl'. See it here at Thompson and Morgan.

Why are there so many different types of flowers?

Someone actually did wonder about this question and his name was Charles Darwin. What he came up with was the 'Evolution of Species through the process of Natural Selection'. If you would like to see this on DVD, there's nothing better than David Attenborough's 'Galapogas'. These are the islands which Charles Darwin visited and what he found there led him to start thinking - big time. The result of this changed the way we thought about where we and every other living thing came from -  Evolution by Natural Selection.

Diagram of the reproductive Parts of a Flower.

Detailed diagram showing the reproductive Parts of a Flower.

Back to the simple standard flower in your backyard. Above: The pollen is found on the top of each stamen (male). This is carried to the stigma (female) where it then grows a pollen tube down to the ovary where it fertilizes an ovule and creates a seed. And as in humans, once an ovule is fertilized it shuts off so that no other pollen can gain access. 

Cratevia religiosa photo. Parts of a flower.

Photo Credit: Eric Guinther.

'Crateva religiosa'. An example of a perfect, typical (complete) flower. You can see that it has petals, many stamens and a single pistil or carpel (which consists of a stigma, a style and below, out of sight - an ovary). Such flowers which have both male and female parts are called bisexual or  'hermaphrodites', (like an earthworm), because they can fertilize themselves without any outside help ie. They are normal or perfect as it's called in the plant world. Most of the flowers we love are of this type. eg.   lilies, hollyhocks, sweet peas, nasturtiums, geraniums - the list is endless. But many Begonias are Imperfect (the  hybrid types, for example. This also means they may be sterile). Growers use other methods to propagate them, such as cuttings, but they end up with a flower which is simply a clone.

Unisexual Plants.

Plants which are unisexual have only female parts or male parts, but not both, and therefore need another plant of the opposite sex to complete fertilization. eg. the Holly Bush -  see below. Other plants have both male and female parts but they are in different parts of the plant or tree. eg. the pine tree has female cones at the top and male cones at the bottom.  

Have some fun like our kids do in the following activity . See if you can get the parts of a flower correct. Just drag and drop:

Interactive fun with a flower. Can you get it right?

Did you get the 'nectaries' right? Learn about them now.  As they say here, a nectary is 'a multicellular glandular structure secreting nectar. Found in flowers and on vegetative parts in some species of plants, often forming projections, lobes, or disk-like structures'. It is also called a gland. This particular part of a flower was certainly new to me. We didn't learn about that in High School Biology, but scientists are always coming up with new findings, one of which is the amazing parts of a flower found in the Daisy Family.

All about Nectaries.

nekonomania / / CC BY

Three different stages of opening out (blooming). The  Calyx, the sepals, the receptacle below, and the beautiful petals of the 'Kalinka' Rose.

This rosebud is waiting to open up ready for the birds and the bees. The parts of a flower involved in reproduction are hidden within. In most types of flowers, the calyx is the green part (very full because of what's inside it). It has a very important role. It supports the growing seed and protects the petals as the flower forms. It is made up of the sepals which open out as the new flower emerges. This is clearly seen in this photo. The receptacle  - which contains the ovary and ovule/s will hold the developing embryo when fertilization is complete.When the seed of a rose is fully formed inside it is called a rose hip. In this photo the receptacle is below the opening calyx. 

All of the parts of a flower are there for one reason: to get fertilized and ensure continuation to the next generation. This is where nature can change different characteristics of a certain species. By genetic mutation. If one flower has a 'faulty' gene it may be a good thing, in which case that gene will be passed on to the next generation. If it's not a beneficial gene, the flower may die, or the species may even die out; but the real basis of natural selection lies in the species which are best adapted to cope with environmental change when it happens. They have very good genes!

Anatomy of a flower. Revision.

Some interesting facts from the above site:

"Other Important Parts of a Flower

Petals. The colorful, often bright part of the flower. They attract pollinators and are usually the reason why we buy and enjoy flowers. And, wait for it, petals are 'only' modified leaves which have evolved beautiful colours and perfumes to attract pollinators! But does that mean we've been tricked? Not really, after all, a rose is beautiful no matter what its different parts are called. 'But not if it were called 'a thistle or a skunk cabbage'. Anne of Green Gables.

Definition from Wikipedia: "Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla". Looking online for proof of this I have come across so many differing opinions on this one. There's even a site which says: 'Yes, Virginia, petals are modified leaves'. 

Sepals are the green parts of the calyx that cover the outside of a flower bud to protect the flower before it opens.

Tepals. Quite often a flower may be said to have tepals. These are added protection for the bud before it opens. A Lily is a perfect example:

Stargazer lily

A lilium flower showing the tepals: the inner three are petals and the outer three are tepals. The Tepals protect the flower before it opens.  I was  given a fresh bunch of these beautiful pink Lilies, just after starting this page and for the first time I was able to see very clearly that there are three large petals (two at the top and one at the bottom) and three smaller petals (tepals) - one at the top and two at the bottom. And we must not forget the other vital part of some flowers which is heavily involved in attracting pollinators - Fragrance. The Stargazer lilies are luxuriously scented. Read about the perfect Oriental Lily. 

The following site has information and photos of the Holly Tree, an Imperfect Flowering Plant. To get flowers, you need to plant a female and a male plant together. Now that is an Imperfect Plant. It is also called Unisexual as opposed to Bisexual. Another is the Pussy Willow.

The Holly Bush. Not so perfect.

And then again, my Mum had a Paw Paw Tree which had both male and female fruits. There are paw paws which are either all female or all male, but these are used in large scale horticulture.  For us, its best to grow the type which has both male and female types of flowers.  You need to plant a few to ensure that they do cross-pollinate often enough. 

An amazing way to reproduce involving the same parts of a flower but in different places on the one plant (tree):

Pine trees have both male and female parts. The female cones form at the top and the males at the bottom. When the reproductive season arrives, the female cones open up and fall to the ground. The males then open up and release their pollen (sperm) which falls onto an open female cone. When this happens, the female cones close up again until the fertilized embryo is ready. Then it opens again to let the embryo out. The baby plant is in the form of a winged seed which can be carried a long way to an ideal location where it can send down its roots and grow into a new pine tree or conifer.  Now that's amazing!


For a more 'academic' description of the parts of a flower:

"A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) or allow selfing (fusion of sperm and egg from the same flower). Some flowers produce diaspores without fertilization (parthenocarpy). Flowers contain sporangia and are the site where gametophytes develop. Flowers give rise to fruit and seeds. Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen.

In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to beautify their environment, and also as objects of romance, ritual, religion, medicine and as a source of food". Wikipedia. So, did you get that? Kids have much more fun learning about the parts of a flower.

Natural Selection.

Flowers and the Fibonacci Numbers.

Oriental Lilies.



Home. Return from Parts of a Flower to Types of Flowers.

'The fact that I can plant a seed and it becomes a flower, share a bit of knowledge and it becomes another's, smile at someone and receive a smile in return, are to me continual spiritual exercises'. 

Leo Buscaglia