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92 Nature

WHAT IS INSIDE A FLOWER?

The male sex organs (anthers and filaments)

surround the female sex organs (ovaries). Flower 

parts are arranged in rings from the outer petals

to the inner ovary. Their purpose is to encourage

. POLLINATION so that. SEEDS can be made.

Flowering plants are divided into two groups. Monocots have one

cotyledon (seed leaf), which is the food store of a seed. They also

have leaves with parallel veins, and flower parts in multiples of

three. Dicots have two cotyledons, leaves with branching, net

veins, and flower parts in groups of four or five.

Sticky stigma

receives pollen during

pollination

Petals are often

brightly coloured

Ovary

contains

the ovum,

or female

sex cell

Anther covered

by pollen

Flowering Plants

This is the most abundant and widespread group of plants on Earth.

Flowering plants are found in most habitats from deserts to polar

regions, and include species of trees, shrubs, and herbs. The flowers

are the reproductive structures that produce new plants.

WHY ARE GRASSES SO IMPORTANT?

The 8,000 species of grasses are plants with small

flowers. Grasses provide food for many grazing

animals, including buffalo and zebra. Grasses can also

provide food such as grains as rice, wheat, and corn.

MONOCOTS AND DICOTS

FLOWER TYPES 3

Some plants have one

flower each. Others

have groups of flowers, called

flower heads. Hogweed has small flowers

arranged in umbrella-like clusters, called

umbels. The head of a sunflower is made up

of many tiny flowers grouped together.

Mullein flowers are arranged in a tall spire.

4 INSIDE A FLOWER

The petals protect the

flower, and also attract

pollinating animals. The

anthers, carried by filaments,

produce pollen. Pollen grains

contain male sex cells. The stigma and

ovary form the female part of the flower.

There are some 250,000

species of flowering

plants. These make up

over 80 per cent of all

the plants on Earth, and

are divided into two

groups:

• The 70,000 species of
  monocots, include
  grasses, lilies, irises,

TYPES OF FLOWERING PLANTS

orchids, and palms.

• The 180,000 species
  of  dicots, include
  roses, magnolias,
  cacti, daisies, and
  lupins, and
  most trees.

Seed

coat

DICOT SEED

LEAVES

MONOCOT SEED

LEAF

A MONOCOT LEAF WITH

PARALLEL VEINS

A DICOT LEAF WITH

NET VEINS

SUNFLOWER

HOGWEED

MULLEIN

flowering

plants