Angiosperms are flowering plants that reproduce sexually through flowers. They dominate terrestrial ecosystems, making up around 90% of all plant species. Key characteristics include producing flowers, fruits, and seeds. Angiosperms were more reproductively successful than earlier plants due to animal pollination and seed dispersal via fruits. They have a double fertilization process and can be annual, biennial, or perennial. Angiosperms occupy nearly all habitats on Earth and are economically important as food, materials, medicines, and ornamentals.

1. ANGIOSPERMS

2. Overview of Angiosperms
• Angiosperms are plants that produce flowers, fruits and seed; and
have their ovules enclosed in an ovary
• It comes from two Greek words ‘angion’ (container) and ‘Sperma’
(seed)
• The largest and most diverse group in the kingdom Plantae, with 68
orders, 416 families, approximately 13,164 known genera and about
400,000 species, and make up about 90% of all plant species on earth

3. • Angiosperms’ use of flowers to reproduce made them more
reproductively successful.
• The pollination of flowers by animals or bees in exchange for nectar
made angiosperms more reproductively successful.
• Angiosperms also began to encase their seeds in fruits, which
provide both extra nourishment and protection for their offspring.
• Produce flowers and fruits to aid in seed dispersal
• Can produce spores which are more stable than seeds from
gymnosperms
• Most importantly, they have vessels that can promote their growth
• Angiosperms appeared on earth during the Cretaceous period.
• Their common ancestor is the gymnosperms

4. General Characteristics - Habitat
• Angiosperms are mostly terrestrial
• A few species are aquatic
• Other forms of habitat include:
• Freshwater e.g. Wolffia, Lemna,
etc.
• Mesophytes e.g. Sunflower;
mulberry
• Xerophytes e.g. Alhagi,
Capparis, etc.
• Succulents e.g. Euphorbia,
Opuntia, etc..

5. • Lithophytes
• Halophytes e.g. Suaeda
• Psammophytes e.g. Yellow
brown Rape
• Some may be found in
marshy habitats e.g.
Rhizophora

6. General Characteristics - Habits
• The habits of a flowering plant can
be determined by its height,
duration and nature of stems
• They are of three main types:
1. Herbs e.g. wheat
2. Shrubs e.g. Jasmine
3. Trees e.g. Dalbergia

7. • Other forms include:
• Trailers e.g. Tribulus
• Creepers e.g. Grass
• Twiners e.g. Ipomoea
• Climbers e.g. grape vine
• Lianas e.g. hiptage
• Epiphytes e.g. Vanda

8. Morphology
• The branch of biology that
deals with the study of the
form, size, and structure of
an organism
• Morphologically,
angiosperms’ bodies are
divided into two main
systems:
1. Root System
2. Shoot System

9. Types of roots
• In flowering plants, there are three
main types of roots, which include:
• Tap roots
• Fibrous roots
• Adventitious roots

10. • Venation in flowering plants : The pattern of
veins on a leaf
• There are two main types:
• Parallel venation
• Reticulate venation

11. Nutrition
• Angiosperms are mostly
autotrophic plants, though a few
are heterotrophic
• The heterotrophic angiosperms
are of three types:
Saprophytes
Parasites
Insectivores

12. Reproduction in angiosperms – Sexual
Reproduction
• This involves the production of male and female gametes
• It is the transfer of the male gamete to the female ovule through the
process of pollination
• Unlike bryophytes and seedless vascular plants, angiosperms and
gymnosperms have a larger, photosynthetic and dominant
sporophyte
• However, the ovules of flowering plants develop into fruits inside the
ovaries

13. • A typical flower has four main parts or
whorl which include:
• Calyx
• Corolla
• Androecium
• Gynoecium

14. • The calyx is composed of green leafy structures known as sepals. It
protects the inner part of the flower, and is the outer most whorl
• The corolla is comprised of petals which are usually brightly colored.
Its function is to attract insects to the flower
• Together, the calyx and corolla are known as the perianth.
• The number of sepals and petals varies depending on the plant;
whether it is a monocot or a dicot.

15. • The androecium which is the
third part of the flower contains
the male reproductive structure.
• It has stamens with anthers that
contain the microsporangia.
• The gynoecium is the inner most
part of the flower.
• It contains the female
reproductive components.
• The carpel is the individual unit
of the gynoecium that has a
stigma, style and ovary

16. Development of pollen grain in the anther
• The male gametophyte develops andreaches
maturity in an immature anther
• In a plant’s male reproductive organ,
development of pollen takes place in a structure
called the microsporangium
• The sporangia, which are usually bi-lobed, are
pollen sacs in which the microspores develop
into pollen grain.
• These are all found in the anther, which is at the
end of the stamen (the long filaments that
support the anther)

18. Pollination : The process by which pollen grains are transferred from the
anther to the stigma of flowers.

19. Life Cycle of a Typical Flowering Plant
• They carry out a unique process known as double fertilization

20. Life Span of a Flowering Plant
• Life span is the time taken by an organism to complete its lifecycle
• On the basis of their lifespan, plants are of four types, which include:
• Ephemerals e.g. Anagalis arvensis
• Annuals e.g. maize, wheat, etc.
• Biennials e.g. henbane, Radish, carrot,etc.
• Perennials e.g. Bamboos, agave, cotton, etc.

21. Distribution of Angiosperms
• One reason for this dominance is the relatively high photosynthetic
• capacity of their leaves.
• • They occupy every habitat on Earth except extreme environments
• such as the highest mountaintops, the regions immediately
• surrounding the poles, and the deepest oceans.
• • They live as epiphytes (i.e., living on other plants)
• They occur abundantly in;
• • shallows of rivers and fresh-water lakes
• • to a lesser extent, in salt lakes and in the sea
• Over 250,000 species of flowering plants have been described, within about 460
• families.

22. Characteristics of Angiosperms
• Angiosperms have developed flowers and fruits.
• • Flower serves as the reproductive organs for the plant.
• • Flowers have a wide array of colors, shapes, and smells, all of which
• are for the purpose of attracting pollinators.
• • Roots, stems, and leaves
• • Xylem & phloem
• Xylem conveys water & dissolved minerals from the roots
• to the shoots
• • Phloem transports food made in the leaves to the roots
• and developing leaves and fruits

23. • Two Classes of Angiosperms
• 1. Monocotyledons (monocots) have a single cotyledon
2. Dicotyledons (dicots) have two cotyledons

24. Morphology of Angiosperms

25. Life cycle of Angiosperms

26. Economic Importance of
Angiosperms
• The flowering plants have a number of uses as food, specifically as
• grains, sugars, vegetables, fruits, oils, nuts, and spices.
• • In addition, plants and their products serve a number of other
needs,
• such as dyes, fibres, timber, fuel, medicines, and ornamentals.