- The systematic study of plants and trees is called Botany.
- The ophrastus is called Father of Botany.
Branches of Botany
• Anatomy – Study of microscopic structure of plants i.e. cells and tissues.
• Biochemistry – The study of chemical reaction in plants plant life processes. This also includes the chemical products of plants and referred as Phytochemistry.
• Biophysics – The application of physics to plant life processes.
• Cytology – The structure, function, and life history of plant cells.
• Ecology – The relationships between plants and the world in which they live, both individually and in larger groups.
• Genetics – Often referred as plant genetics is study of plant heredity and variation.
• Molecular Biology – The structure and function of biological macromolecules, including biochemical and molecular aspects of genetics.
• Morphology – The macroscopic plant form. Morphologists also study the evolution and development of leaves, roots and stems.
• Paleobotany - The biology and evolution of fossil plants.
• Physiology - The functions and vital processes of plants. Photosynthesis and mineral nutrition are two exampIes of subjects studied by plant physiologists.
• Systematics – The evolutionary history and relationships among plants.
• Systems Ecology- This branch of botany uses mathematical models to show concepts like nutrient cycling.
• Taxonomy- This is the sub discipline of identifying, naming, and classifying plants.
Classification of Plantae
Plant Kingdom is divided over two groups-
1. Cryptogamus i.e. Plant Without Seed and
2. Phanerogames (Plat with seed)
The seedless plants i.e. Cryptogamus are of three types-
Again the Thalophyta can be classified over two groups-
1. Algae and 2. Fungi
The seed bearing plants i.e Phanerogames are of two types-
1. Gymnospermae and
The Angiospermae are classified over two groups-
1. Monocotyledons and
• Thalophyta is a sub group of Cryptogamus Plants and largest group of the botanical kingdom.
• The body of system of this group is like Thalus and can not be identified into parts like root, stem and leaves etc.
• No conducting tissue found in this group of plants.
• The plants of this group are of two types, Algae and Fungi.
• In botany, the study of algae is called Phycology.
• Normally Alage contains chlorophyll and autotrophic mode of nutrition.
• An algae plant may be unicellular, colonial, or filamentous. The Body structure of Algae is Thalus like.
Uses of Algae
• Algae can be grown to produce biomass, which can be burned to produce heat and electricity.
• Algae can be used to make Biodiesel (see algaculture), Bioethanol and biobutanol.
• Algae are used in Wastewater Treatment facilities, reducing the need for greater amounts of toxic chemicals than are already used.
• Algae can be used to capture fertilizers in runoff from farms. When subsequently harvested, the enriched algae itself can be used as fertilizer.
• An Astronaut can get food enriched with protein, oxygen and water by sowing the chlorella algae in the aircraft’s tank; this algae is also known as space algae.
• Systematic study of Fungi is called mycology.
• Fungi have no chlorophyll, no chlorophyll, central career is tissues; Fungi is a Thalophyte.
• Fungi found everywhere, air, water, land, plants, animals all are perfect environments for living a fungi.
• The type of fungi present in a soil determines what kind of plat will grow in that soil and what kind of animal may live.
• Fungi are heterotrophs and get nutrients by absorption.
• The parasitic obtain nutrients from living beings.
• Unlike plants, fungi cell walls are build of carbohydrates.
• Fungi may cause serious diseases in plants. Fungi attack all parts of a plant and can damage plant translocation tissues; thereby killing a plant in shorter time. Some of the most common fungal diseases are damping off plants, leaf spot, anthracnose and rust.
• This is the first division of land plants. Within this group includes more than 25000 plant species.
• Brophyta has no xylem and phloem tissues.
• The body of a bryophyta plant may be like Thalus in shape and leafy erect structure similar as in moss.
• Brophyta has no roots, stem and leaves.
• Bryophyta are also referred as Amphibian plants.
• The Moss Sphagnum has capacity to absorb water 18times than its won mass and hence preferred by gardeners for wet treatment of plants when shifting from one place to another.
• The moss Sphagnum is used as fuel and antiseptic.
• The plants of this group are found in wet shady places, forests zones and mountain regions.
• The plant body can be divided over root stem and leaves.
• In this plat group reproduction takes place through spores produced inside the sporangia.
• The Pterridophyta plants have conducting tissues but xylem does not have vessels, also phloem does not have cells.
• Some examples of Pterridophyta plants are Ferns, Azolla, Pteridium, Lycopodium.
Phanerogamus or Floral Plant
The Phanerogams are flowering plants or seed-bearing plants. They are the most advanced plants. These plants have well-developed roots, stems, leaves and flowers.
Phanerogams are divided into two main gropus.
• Gymnosperms are naked – seeded plants, which mean that, in these plants the seeds are not enclosed in a fruit.
• These plants are mostly found in hills. Some of these possess ‘cones’ and are hence called ‘conifers’.
• The examples of gymnosperms are Pine, fir, cycas etc.
• The pollination in gymnosperm plants takes place via air.
• There are between 700 and 900 extant or currently living species of Gymnosperms.
• There are 4 major divisions of plants within the gymnosperms:
1. Ginkgophyta (Ginkgo: maidenhair tree),
2. Cycadophyta (Cycads),
3. Gnetophyta (Gnetophytes), and
4. Pinophyta or Coniferophyta (the conifers).
Gymnosperms have major economic uses. Pine, fir, spruce, and cedar are all examples of conifers that are used for lumber. Some other common uses for gymnosperms are soap, varnish, nail polish, food, gum, and perfumes.
• Angiosperms are closed – seeded plants. In these plants the seeds are enclosed in a fruit. Flower is the reproductive structure of the angiosperms. Mango, apple, rose, sunflowers and pea are examples of flowering plants.
• Angiosperms are further classified as:
• Monocotyledons or Monocot in short these are plants which the seed has only one cotyledon. All grasses, bamboo, sugarcane, wheat, rice, banana and palms are monocots.
• Dicotyledons or Dicot in short, these are plants in which the seed has two cotyledons. Bean, gram, pulses, most fruit trees, vegetables and ornamental plants are dictos.
Some common dicot plants examples include: