Characteristics of Flowers – OLabs

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Characteristics of Flowers The plant kingdom contains an amazing rangeof diverse forms which are classified based on their similarities and differences.

Planttaxonomy is the science that finds, identifies, describes, classifies and names plants.

Thefield identification of plants is based primarily on morphological features, particularly thefloral characteristics.

In this video we will look at the characteristics of the petuniaflower, long bean flower, gloriosa lily flower and asparagus flower.

Materials required: Petunia, long bean, gloriosa lily and asparagusflower, forceps, blade, glass slide, needle, cover slip, and dissection microscope.

Let's begin with the petunia flower.

External Observations Petunia is a genus of flowering plants whichcomes under the family Solanaceae.

Petunia flowers have different colours, although theyare most often purplish in colour.

We can observe that petals of petunia are united,so it is gamopetalous flower.

Similarly, the sepals are also united and become a gamosepalousflower.

Sepals and petals meet at their edges without overlapping, so the flower shows valvateaestivation.

Petals look like a funnel, so it is an infundibuliform flower.

Cross section of a Petunia Flower Using a blade, carefully cut the flower intwo.

We can see that petunia flower can be divided into two equal halves through anyvertical plane, so it is an actinomorphic flower.

Inside the flower we can see the stamens,the male reproductive organ, and carpel, the female reproductive organ.

In the petuniaflower, stamens are fused with petals, so it is epipetalous flower.

Let's take the count of the number of eachwhorl in a petunia flower, Carefully remove floral leaves of each whorlusing a forceps and place them on a white paper.

We can observe that petunia flowershave 5 petals, 5 sepals and 5 stamens.

The filament of the stamen is attached to thebase of the anther, so the petunia flower has a basifixed anther.

The ovary has twocarpels, so it is a bicarpellary gynoecium.

Cross Section of Ovary Using a blade, cut thin section of ovary.

Mount the section on a slide in a drop of water and examine under a dissecting microscope.

The ovary is partitioned into chambers and the placentae are borne along the septa ofthe ovary, so it has axile placentation.

We can observe there are two chambers in theovary, so it is bilocular ovary.

Reasons for Identification Infundibuliform corolla.

Stamens epipetalous.

Bicarpellary gynoecium and axile placentation.

Long Bean Flower External Observations Long Bean is a genus of flowering plant comingunder the family Fabaceae.

We can observe that the long bean flower has a bract anda stalk.

Sepals of the flower are united, so it is gamosepalous flower.

Petals of theflowers are free from each other, so it is a polypetalous flower.

Carefully observe thearrangement of petals.

We can see that the posterior petal is large and overlaps thetwo lateral petals, which overlap the two anterior petals.

Cross Section of a Long Bean Flower Using a blade, carefully cut the flower intwo.

We can see that the flower can be divided into two equal halves only along one verticalplane, so it is a zygomorphic flower.

Inside the flower we can see the stamens, the malereproductive organ, and carpel, the female reproductive organ.

Let's take the count of the numbers in each whorl of the long bean flower.

Carefully remove the floral leaves of each whorl using a forceps and place them on atable.

We can observe that the long bean flower has 5 petals, 5 sepals and 10 stamens.

Ninestamens unite to form a tube.

The tenth stamen is free, so it is a diadelphous stamen.

Thefilament of the stamen is attached to the base of the anther, so the flower has a basifixedanther.

The ovary has one carpel, so it is a monocarpellary gynoecium.

Cross Section of Ovary Using a blade, cut a thin section of ovary.

Mount the section on a slide in a drop of water and examine under a dissecting microscope.

There is only one chamber in ovary, so it is an unilocular ovary.

Reasons for Identification Flower Zygomorphic.

Odd sepals anterior.

Stamens diadelphous.

Monocarpellary gynoecium, ovary unilocular.

Gloriosa Lily Flower External Observations Gloriosa superba is a genus of flowering plantcoming under the family Liliaceae.

We can observe that the floral leaves of each whorlare in threes or multiples of three, so it is trimerous flower.

The sepals and petalslook very similar, so they are called tepals.

There are 6 tepals arranged in two whorlsof three each.

In the bud, the pale green tepals face downward.

As it matures, the tepalselongate and wrinkle and gradually arch backward while sequencing through a spectrum of colorfrom green to yellow to scarlet.

The stamens are extremely prominent and spread outwardin graceful curves that follow the tepals in their backward progression.

The style isdeflected at base and projects from the flower more or less horizontally.

Position of ovaryis superior to other floral parts.

Cross Section of Gloriosa Flower Using a blade, carefully cut the flower intwo.

We can see that flower can be divided into two equal halves through any verticalplane, so it is an actinomorphic flower.

In the gloriosa flower stamens are fused withthe perianth, so it is epiphyllous flower.

Let's take a count of numbers in each whorlof the Gloriosa flower.

Arrange the floral leaves of each whorl ona table.

We can observe that the Gloriosa flower has 6 tepals, 6 stamens and an ovarywith three carpels.

Cross section of Ovary Using a blade, cut a thin section of ovary.

Mount the section on a slide in a drop of water and examine under a dissecting microscope.

The ovary is partitioned into several chambers and the placentae are borne along the septaof the ovary, so it is axile placentation.

There are three chambers in the ovary, soit is a trilocular ovary.

Each locule contains two ovules.

Reasons for Identification Flower is trimerous.

Petaloid Perianth in two whorls of three each.

Epiphyllous stamen.

Ovary tricarpellary, trilocular with axile placentation.

Asparagus Flower External Observations Asparagus is a genus of flowering plant comingunder the family Liliaceae.

We can observe that the floral leaves of each whorl are inthrees or multiples of three, so it is trimerous flower.

The sepals and petals look very similar,so they are called tepals.

There are 6 tepals arranged in two whorls of three each.

Positionof ovary is superior to other floral parts.

Cross Section of Asparagus Flower Using a blade, carefully cut the flower intwo.

We can see that flower can be divided into two equal halves through any verticalplane, so it is an actinomorphic flower.

In the asparagus flower stamens are fused withthe perianth, so it is epiphyllous flower.

Let's take a count of numbers in each whorlof the Asparagus flower.

Arrange the floral leaves of each whorl ona table.

We can observe that the Asparagus flower has 6 tepals, 6 stamens and an ovarywith three carpels.

Cross section of Ovary Using a blade, cut a thin section of ovary.

Mount the section on a slide in a drop of water and examine under a dissecting microscope.

The ovary is partitioned into several chambers and the placentae are borne along the septaof the ovary, so it is axile placentation.

There are three chambers in the ovary, soit is a trilocular ovary.

Each locule contains two ovules.

Reasons for Identification Flower is trimerous.

Petaloid Perianth in two whorls of three each.

Epiphyllous stamen.

Ovary tricarpellary, trilocular with axile placentation.

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