MORPHOLOGY OF FLOWERING PLANTS in 1 Shot | All concepts Covered | UMEED NEET in Pure English
Ovary and Flower Structure
Ovary Types: The ovary is central in flower structure; there are three types of flower ovary positions:
Hypogynous (Inferior): Ovary is located below the other floral parts. Example plants include guava and cucumber.
Perigynous (Half-Inferior): Ovary is partially embedded within a cup-like thalamus, having other floral parts arise at the same level. Examples include peach and rose.
Epigynous (Superior): Ovary is at the top, above all other floral parts, making it inferior due to its position below other structures. Example plants include guava and sunflower.
Fruit Classification
Definition of Fruit: A mature ovary that protects seeds and aids in their dispersal.
Categories of Fruits:
Fleshy Fruits: Soft and edible pericarp surrounding seeds. Examples include:
Berries (e.g., grapes, bananas): Have multiple seeds with fleshy pericarp.
Drupes (e.g., cherries, peaches): One seed enclosed in a hard endocarp.
Pomes (e.g., apples, pears): Have a core containing seeds surrounded by fleshy tissue.
Dry Fruits: Hard or papery pericarp, further classified into:
Dehiscent Fruits: Split open at maturity to release seeds (e.g., peas, beans).
Indehiscent Fruits: Do not split open and remain intact (e.g., nuts, grains).
Seeds and Their Structure
Definition of Seed: A fertilized ovule containing an embryo meant to develop into a new plant.
Parts of a Seed:
Seed Coat: Protective outer layer.
Embryo: Young plant part that will grow into a new plant.
Endosperm: Provides nourishment to the developing embryo.
Types of Seeds:
Monocotyledons: Seed with one cotyledon (e.g., corn, rice).
Dicotyledons: Seed with two cotyledons (e.g., beans, peas).
Flower Morphology and Parts
Flower Structure: Comprised of various parts including the calyx (sepal), corolla (petals), androecium (stamens), and gynoecium (carpels).
Stamens: Male reproductive part consisting of filament and anther, which produces pollen grains.
Gynoecium: Female reproductive structure containing stigma, style, and ovary, where ovules are found.
Floral Estivation Types
Valvate Estivation: Petals are free and barely touch at the edges. Seen in plants like Calotropis.
Twisted Estivation: One petal overlaps another in alternate directions. Found in China rose and hibiscus.
Imbricate Estivation: Overlapping petals but not in a specific pattern. Seen in Calia and Gulmohar.
Vexillary Estivation: A characteristic in the pea family where one large petal overlaps two smaller ones.
Placentation Types
Marginal Placentation: Seen in peas; ovules are attached on the ventral side forming a ridge in a one-chambered ovary.
Axile Placentation: Multilocular ovary with ovules borne on a central axis seen in lemon and tomato.
Parietal Placentation: Initially unilocular ovary with ovules attached to the inner wall, later becoming bipartite due to false septum formation, seen in mustard.
Free Central Placentation: Similar to axile but lacks septa, thus unilocular. Observed in Dianthus.
Basal Placentation: One ovule attached at the base; noted in sunflower and marigold.
Economic Importance of Plant Families
Brassicaceae (Mustard Family)
Includes popular vegetables and cooking oils (e.g., mustard oil).
Notable for tetradynamous stamens and actinomorphic flowers.
Fabaceae (Legume Family)
Consists of pulses (e.g., beans, gram) known for protein content.
Characterized by diadelphous stamens, pinnate leaves, and marginal placentation.
Nodules for nitrogen fixation observed in roots.
Malvaceae (Hibiscus Family)
Includes hibiscus and okra, show monadelphous conditions in stamens.
Flowers are actinomorphic, often solitary or in cymose clusters.
Poaceae (Grass Family)
Encompasses all cereal grains (e.g., rice, wheat, corn) with fibrous root systems.
Characterized by caryopsis fruits where seed coat and fruit wall are fused.
Flowers are generally small with wind pollination.