🌺 Morphology of Flowering Plants

1. The Root

Radicle forms the primary root. Types: Tap root system (dicots), Fibrous root system (monocots), and Adventitious roots (arise from parts other than radicle).

Regions of the Root

Root Cap → Region of Meristematic Activity → Region of Elongation → Region of Maturation (bears root hairs).

Modifications: For food storage (Carrot, Sweet potato), support (Prop roots in Banyan, Stilt roots in Maize), respiration (Pneumatophores in Rhizophora).

2. The Stem

Develops from the plumule. Bears nodes and internodes.

Modifications: Underground storage (Potato, Ginger, Turmeric), Tendrils for support (Gourds), Thorns for protection (Bougainvillea), Photosynthetic (Opuntia).

3. The Leaf

A lateral, flattened structure for photosynthesis. Consists of leaf base, petiole, and lamina.

  • Venation: Arrangement of veins. Reticulate (dicots) and Parallel (monocots).
  • Phyllotaxy: Pattern of leaf arrangement on stem. Alternate (Mustard), Opposite (Guava), Whorled (Alstonia).

4. The Flower and Inflorescence

Inflorescence: Arrangement of flowers on the floral axis. Racemose (main axis continues to grow) and Cymose (main axis terminates in a flower).

A typical flower has four whorls: Calyx (sepals), Corolla (petals), Androecium (stamens/male), Gynoecium (carpels/female).

Aestivation

The mode of arrangement of sepals or petals in a floral bud. Types: Valvate, Twisted, Imbricate, and Vexillary (Pea).

5. Fruit and Seed

Fruit: A mature or ripened ovary. A fruit formed without fertilization of the ovary is called a parthenocarpic fruit.

Seed: Composed of a seed coat and an embryo (radicle, embryonal axis, and 1 or 2 cotyledons).