NEET NEW TOPICS
Morphology of Flowering Plants
Poaceae
Poaceae Family Overview
1. Introduction
Family Name: Poaceae (or Gramineae), commonly known as grasses.
Rank: Fifth-largest plant family, following Asteraceae, Orchidaceae, Fabaceae, and Rubiaceae.
Economic Importance: The most economically important plant family, providing staple foods from domesticated cereal crops like maize, wheat, rice, barley, and millet.
2. Classification
Domain: Eukarya
Kingdom: Plantae
Division: Angiospermae
Class: Monocotyledonae
Order: Poales
Family: Poaceae
3. Vegetative Characters
3.1 Habit
Herbs, shrubs, or trees.
3.2 Root
Fibrous root system.
3.3 Stem
Erect, cylindrical, herbaceous, or woody.
3.4 Leaves
Sheathing leaf base, sessile.
4. Floral Characters
4.1 Inflorescence
Spikelet.
4.2 Flower
Bracteate, zygomorphic.
Bisexual (e.g., Rice – Oryza sativa) or rarely unisexual (e.g., Maize/Corn – Zea mays).
4.3 Perianth
Reduced to two scales, called lodicules.
4.4 Androecium
Stamens: 3 to 6.
4.5 Gynoecium
Monocarpellary with a superior, unilocular ovary containing a single ovule.
Placentation: Basal.
4.6 Fruit
Caryopsis (one-seeded fruit).
4.7 Seed
Endospermic.
4.8 Floral Formula
Br.% P2 A3-6 G1
Br.% : Bracteate, zygomorphic flower.
P2 : Two lodicules (reduced perianth).
A3-6 : 3 to 6 stamens.
G1 : Monocarpellary, superior ovary.
5. Economic Importance
5.1 Cereals
Wheat: Triticum aestivum.
Rice: Oryza sativa.
Maize: Zea mays.
5.2 Millets
Jowar: Sorghum vulgare.
5.3 Other Uses
Doob Grass: Cyanodon dactylon – Used in traditional medicine and religious purposes.
Sugarcane: Saccharum officinarum – Major source of sugar production.
Lemon Grass – Used as a culinary herb for its citrus-like flavor and scent.
Key Notes
Global Food Production: Rice, wheat, and maize contribute the maximum to global food production.
Major Crop of Asia: Rice is the major crop of Asia.
Unique Features: The reduced perianth (lodicules) and one-seeded caryopsis are characteristic features of Poaceae.
