Reproductive morphology of flowering plants: A flower

pedicellete flower

A flower with stalk

NPC-system.

A special system has been devised to describe the Number, Position and Character of the apertures in pollen grains.

Pentamerous flower

Floral parts in five's or multiples of five

Tetramerous flower

Floral parts in four's or multiples of four

Trimerous flower

Floral parts in three's or multiples of three

Campanulate corolla

Gamopetalous , - Five petals are arranged like bell. eg. Tobacco, Raspberry, Campanula.

Funnel shaped or infundibuliform corolla

Gamopetalous ,Funnel like petals arrangement eg. Datura, Railway creeper.

Tubular corolla

Gamopetalous ,Petals are like tube eg. Disc florets of sunflower.

Involucel

Group of bracteole is called involucel.

Monocarpellary

Gynoecium having one carpel e.g. pea.

Style

It is the elongated tube connecting ovary and stigma.

Gynoecium

It is the fourth and second essential whorl of the flower. It is female part of the flower comprising of the inner whorl of megasporophylls in the form of carpels bearing ovules. It consists of ovary, style and stigma.

Ovary

It is the swollen (enlarged) basal part, one to many chambered (called locules) containing ovules which get fertilized to form seeds and the ovary forms the fruit.

Androecium

It is the third whorl of the flower. It is considered as the male part of the flower, is made up of stamens or microsporophylls.

Stigma

It is usually at the tip of the style and is the receptive surface for pollen

Dioecious flower

Male and female flower occur on different plants e.g., papaya

Cruciform corolla

Polypetalous corolla, 4 petals are present in it. The lower narrow part of petal is called claw while the outer broad part is called limb. These petals are arranged crosswise. eg. Radish, Mustard.

Caryophyllaceous corolla

Polypetalous corolla, It consists of 5 petals the claw of petals are short and the limb of petals from right angle to the claw eg. Dianthus.

Rosaceous corolla

Polypetalous corolla,It consist of 5 or more petals. Claws are absent in it and limbs are spread regularly outwards. eg. Rose, Coconut.

Petaloid Tepals

Tepals in most monocots, colored, e.g., Iridaceae.

Reduced Tepals

Tepals in most monocots, e.g., Gramineae

non-essential organs or accessory organs

The calyx and corolla do not have a direct role in these processes

Personate corolla

Zygomorphic gamopetalous corolla, In this case the corolla is bilabiate but the two lips are near to each other eg. Antirrhinum

Bilabiate corolla

Zygomorphic gamopetalous corolla, The petal of gamopetalous corolla is divided into two lips. The place between two lips is called corolla mouth. eg. Ocimum, Salvia.

Ligulate corolla

Zygomorphic gamopetalous corolla, The upper part of corolla is long, flattened which is attached with short narrow tube. eg. Ray florets of sunflower.

Papilionaceous corolla

Zygomorphic polypetalous corolla, Five petals are present. It's posterior petal is largest and is known as standard or vexillum. Standard covers two lateral petals which are called as wings and the innermost basal petals are united to form a keel or carina. Both lateral parts cover the keel. eg. Pea, Gram, Arher

apocarpous

carpels are free e.g. Ranunculus, lotus.

syncarpous

carpels are fused e.g. tomato, mustard

Diadelphous

filaments fused to form two bundles e.g. pea

Complete/Perfect flower

flower All 4 floral whorls present

Pollen grain

germinates by the production of germination tubes, which penetrate the pollen wall (sporoderm) through certain holes called apertures.

A flower

is a modified shoot specialized to carry out sexual reproduction in higher plants. because it has (i) nodes very close to one another and (ii) floral leaves arranged in successive whorls.

The pollen wall (or sporoderm)

is generally distinctly layered. There are 3 principal layers, from outward to inward: 1- Perine (always decayed). 2- Exine (2-layers; sexine & nexine). 3- Intine.

Bracteate flower

is the flower which have bract

bracteoles

small leaf-like structures are present in the middle of pedicel.

bract

Like a branch, it arises in the axil of a small leaf-like structure, is usually situated at the base of pedicel.

sessile

A flower without stalk

Parts of a flower

A typical flower consists of following parts: 1. Bracts and Bracteoles 2. Thalamus 3. Whorls of flower a. Calyx b. Corolla c. Androecium d. Gynoecium

isomery

Occurrence of the same number of floral parts in different floral whorls of a flower

Unisexual flower

Only one reproductive organ present

Petaloid Perianth

Perianth in most dicots colored, e.g., Nyctaginaceae

Sepaloid Perianth

Perianth in most dicots, green in color. e.g., Chenopodiaceae

Bisexual flower

Both gynoecium and androecium present in the same flower.

Monoecious flower

Both male and female flower occur on same plant e.g., cucumber Cocos, Ricinus, Colocasia, Zea, Acalypha

Achlamydeous Flower

Flowers are bare without sepals and petals eg. piperaceae

Spathe

In flowers when large bract completely encloses whole inflorescence, then it is called spathe. eg. Banana, Maize.

Tetradynamous

Six stamens, inner four are long and outer two are short e.g., mustard

Glumes

Small, dry, scaly bracts are called Glumes. eg. Wheat, Grass.

Epigynous flower & inferior ovary

The margin of thalamus grows upward enclosing the ovary completely and getting fused with it, the other parts of flower arises above the ovary, e.g. Guava, Cucumber and ray florets of sun flower

Calyx

The outermost whorl of flower is called calyx. Each member of this whorl is called sepal

Monocarpic Plant

The plant which produces flowers and fruits only once in life e.g. Pea, Mustard, Bamboo, Agave.

Polycarpic Plant

The plants which produces flowers and fruits many times in life, e.g. Pear, Mango,

function of the calyx

The primary function of the calyx is protective. * It protects the inner parts of the flower from mechanical injury, rain and excessive sun shine, and from drying out in the bud condition. * Green in colour, it can also do the phosynthetic function. * When petaloid, it performs the function of attracting insects for pollination. * When spiny, its function is defensive and as * pappus, it helps in the dispersal of fruit.

Corolla

The second whorl of flower is called corolla and each member of it is called Petals, They help in attracting insects for pollination.

receptacle (thalamus or torus).

The terminal part of the axis of a flower, which supports all the floral appendages (i.e., sepals, petals, stamens and carpels), it consists of several crowded nodes which are separated by condensed internodes.

Involucre

The whorl of bract surrounding peduncle is called involucre

Actinomorphic

When flower is divided by any vertical plane into two equal halves, then it is called actinomorphic flower eg. Mustard, China rose, Datura, Chilli

Hypogynous flower & superior ovary

When petals, sepals and stamens are situated below the ovary, e.g Chinarose, Brinjal.

Asymmetrical

When the flower cannot be divided into two equal halves from any plane, then it is called asymmetrical flower. eg. Canna.

Zygomorphic

When the flower is divided into two equal halves only by one vertical plane, then it is called zygomorphic flower eg. Pea, Bean, Gulmohur, Cassia.

Petaloid bract

When the size of bract of flower is greater than size of flower and these are of various coloured then it is called petaloid bract. eg. Bougainvillea.

inaperturate

When the sporoderm has no obvious apertures the pollen grain

Polygamous Plant

When unisexual (male or female), bisexual and neuter flowers are present on the same plant e.g. Mango, Polygonum.

pedicel

a short stalk ,The internode of the branch that lies below the receptacle,

) Gamosepalous and Gamopetalous (gamo - united)-

all sepals or petals are fused.

essential organs

androecium and gynoecium because they have a direct role in reproduction i.e. pollination and fertilization which lead to development of fruit and seeds from flower.

sepals

are usually green in colour, but sometimes, become brightly coloured then, said to be petaloid as in Caesalpinia pulcherrima.

Syngenesious

filaments are free but anthers are fused e.g. sunflower

Monadelphous

filaments fused into one bundle but anthers are free e.g. china rose

Polyadelphous

filaments fused to form many bundles e.g., lemon

Incomplete/Imperfect flower

flower Any one or more of floral whorl is absent

Neuter flower

flower Both stamens and carpels are absent

heteromerous

flowers have different number of parts in each whorl. This condition

Didynamous

four stamens, two short and two long e.g. tulsi

stamen

has a slender stalk called filament, bearing the anther (microsporangial sorus). Usually the anther consists of two lobes. The two lobes of an anther are connected by a tissue called connective. Each anther lobe has two pollen sacs (microsporangia). Each pollen sac consists of innumerable Pollen grains (microspores).

Polycarpellary

many carpels (e.g. china rose).

Pistillate flower

or female flower Only carpel present

Staminate flower

or male flower Only stamens present

Polysepalous and Polypetalous (poly - free)-

sepals or petals are free respectively

Epipetalous

stamens are attached to petals but anthers are free e.g., brinjal

Synandrous

stamens are fused throughout the length e.g., cocks-comb.