→ The . flowering plants exhibit enormous variation in the shape, size and structure, mode of nutrition, life span, habit, and habitat.

→ Plants are differentiated into root, stem, and leaves with flowers and fruits of various types.

→ The roots system absorbs water and minerals from the soil and anchors the plants.

→ Stems are generally negatively geotropic and aerial.

→ Leaves are the main photosynthetic organs of the plant. The outline of the leaf-blade margin and tip shows an enormous variation. There are structural modifications of root, stem, and leaves depending upon various functions.

→ The flower is a modified shoot meant for sexual reproduction.

→ The flowers are arranged in different types of inflorescence. After fertilization, the ovary is converted into fruits and ovules into seeds.

→ Seeds either may be monocotyledons or dicotyledons. On the basis of their development fruits may be of different types.

→ A flowering plant is described in definite sequence by using scientific terms.

→ Scientific description of a few selected plant families including their economic importance has been given as a sample for the study.

→ Root system: The root system normally lies underground and consists of the main root and its branches.

→ Shoot system: The shoot system is normally aerial and consists of the main stem, lateral branches, and leaves.

→ Taproot system: The taproot and its branches together constitute a tap root system.

→ Primary root: The first root is generally formed by the elongation of the radicle and is called the primary root.

→ Secondary roots: It continues growing and produces lateral roots called secondary roots.

→ Adventitious root system: Roots that develop from any part of a plant other than the radicle or its branches are called adventitious root systems.

→ Modifications of root: Modifications are the morphological changes in an organ to perform certain special functions other than or in addition to the normal functions.

→ Buds: A bud is a compacted under developed shoot having a growing point, surrounded by closely placed immature leaves.

→ Runners: They are sub-aerial weak, slender lateral branches, that grow horizontally along the soil surface.

→ Offsets: They are one internode long, stout, slender, and condensed runner found in rosette plants at the ground or water level.

→ Adaptation: Adjustment of an organism to its environment.

→ Gynomonoecious: A plant having female and intersexual flowers e.g. sunflower.

→ Haustorium: A projection that acts as a penetrating and absorbing organ.

→ Radicle: Portion of the plant embryo that develops into the primary root.

→ Transpiration: The giving off water vapor from the surface of the leaf.