Morphology of Flowering Plants
NCERT Line-by-Line Breakdown for NEET 2026
Unit 2: Structural Organisation in Plants and AnimalsMorphology is the study of external structure. In flowering plants (Angiosperms), we study the Root, Stem, Leaf, Flower, Fruit, and Seed. This chapter is crucial because NEET 2026 has explicitly listed five specific families to study!
[Image of parts of a flowering plant]1. The Root
The root system mainly absorbs water and minerals. In majority of dicots, the direct elongation of radicle leads to the formation of the primary root.
🌱 Tap Root System
Primary root and its branches constitute the tap root system.
Example: Mustard.
🌾 Fibrous Root System
Primary root is short-lived and replaced by large number of roots originating from the base of the stem.
Example: Wheat (Monocots).
🎋 Adventitious Roots
Roots arise from parts of the plant other than the radicle.
Example: Grass, Monstera, Banyan tree.
Modifications of Root
- Storage: Tap roots of Carrot, Turnip; Adventitious roots of Sweet Potato.
- Support: Prop roots (Banyan), Stilt roots (Maize, Sugarcane).
- Respiration: Pneumatophores in Rhizophora (grow vertically upwards in swampy areas).
2. The Stem
Develops from the plumule. Bears nodes and internodes.
| Modification Type | Function | Examples |
|---|---|---|
| Underground Stem | Food storage, Perennation. | Potato, Ginger, Turmeric, Zaminkand, Colocasia. |
| Stem Tendrils | Climbing (Support). | Gourds (Cucumber, Pumpkin, Watermelon), Grapevines. |
| Thorns | Protection from browsing animals. | Citrus, Bougainvillea. |
| Phylloclade | Photosynthesis (Flattened/Cylindrical). | Opuntia (Flattened), Euphorbia (Cylindrical). |
| Offsets | Vegetative Propagation (Aquatic). | Pistia, Eichhornia. |
3. The Leaf
The most important vegetative organ for photosynthesis. Originates from shoot apical meristem in acropetal order.
🍃 Venation & Phyllotaxy
- Reticulate Venation: Dicots.
- Parallel Venation: Monocots.
- Alternate Phyllotaxy: Single leaf at each node (China rose, Mustard, Sunflower).
- Opposite Phyllotaxy: Pair of leaves at each node (Calotropis, Guava).
- Whorled Phyllotaxy: More than two leaves at a node (Alstonia).
4. Inflorescence & Flower
Inflorescence: Arrangement of flowers on the floral axis.
- Racemose: Main axis continues to grow; flowers in acropetal succession.
- Cymose: Main axis terminates in a flower; flowers in basipetal succession.
🌸 Flower Parts & Symmetry
Symmetry:
- Actinomorphic (Radial): Mustard, Datura, Chilli.
- Zygomorphic (Bilateral): Pea, Gulmohar, Bean, Cassia.
- Asymmetric: Canna.
Position of Ovary:
5. Important Families (New Syllabus)
According to the NEET 2026 notification, you must know these families. Here is a quick cheat sheet for their unique features.
| Family | Key Floral Characters | Economic Importance |
|---|---|---|
| Fabaceae (Leguminosae) | Papilionaceous corolla (Vexillary aestivation), Diadelphous stamens (9+1), Marginal placentation. | Pulses (Gram, Arhar), Edible oil (Soybean), Dye (Indigofera), Fodder (Sesbania). |
| Solanaceae (Potato Family) | Persistent calyx, Epipetalous stamens, Axile placentation (swollen placenta). | Vegetables (Tomato, Brinjal), Spice (Chilli), Medicine (Belladonna, Ashwagandha). |
| Liliaceae (Lily Family) | Perianth (Tepals), Epiphyllous stamens, Tricarpellary syncarpous ovary. | Ornamentals (Tulip), Medicine (Aloe), Colchicine. |
| Cruciferae (Brassicaceae) | Tetramerous, Cruciform corolla, Tetradynamous stamens (2+4), Replum (false septum). | Mustard (Oil), Cabbage, Cauliflower. |
📝 Rapid Fire MCQs
Q1. Pneumatophores occur in:
- A) Halophytes
- B) Free-floating hydrophytes
- C) Submerged hydrophytes
- D) Insectivorous plants
Click to check Answer
Answer: A) Halophytes (e.g., Rhizophora in salty marshes).
Q2. Vexillary aestivation is characteristic of the family:
- A) Fabaceae
- B) Asteraceae
- C) Solanaceae
- D) Brassicaceae
Click to check Answer
Answer: A) Fabaceae (Pea family).