DEUS LEARNINGS
NEET NEW TOPICS
Morphology of Flowering Plants
Compositae (Asteraceae) Notes
Compositae (Asteraceae)
Systematic Position
- Domain: Eukarya
- Kingdom: Plantae
- Division: Angiospermae
- Class: Dicotyledonae
- Order: Astarales
- Family: Compositae (Asteraceae)
General Information
- Common Name: Sunflower family
- Description: Largest family of angiosperms with the most genera and species.
- Evolutionary Status: Most advanced among angiosperms.
Vegetative Characters
- Habit: Herbs, shrubs, or rarely trees
- Root: Tap root system
- Stem: Usually herbaceous, erect, branched, solid
- Leaves: Mostly alternate, exstipulate, simple pinnately or palmately or compound with reticulate venation
Floral Characters
- Inflorescence: Capitulum or head
- Flower: Epigynous, usually pentamerous, bisexual or unisexual, actinomorphic or zygomorphic, bracteate or ebracteate
Ray Florets
- Type: Unisexual, zygomorphic
- Calyx: Pappus or scaly, persistent
- Corolla: Petals 5, gamopetalous
- Androecium: Absent
- Gynoecium: Bicarpellary, syncarpous, ovary inferior, unilocular, basal placentation
- Floral Formula: Br.% K(papus) C(5) Ao G(2)
Disc Florets
- Type: Bisexual, actinomorphic
- Calyx: Pappus
- Corolla: Petals 5, gamopetalous
- Androecium: 5 stamens, epipetalous, syngenesious, dithectus
- Gynoecium: Bicarpellary, syncarpous, ovary inferior, unilocular, basal placentation
- Fruit: Cypsella
- Seed: Non-endospermic
- Floral Formula: K(pappus) C(5) A5 G(2)
Economic Importance
- Sunflower (Helianthus annuus): Ornamental and source of unsaturated edible oil.
- Marigold (Tagetus erectus)
- Carrot Grass or Congress Grass (Parthenium): Weed growing in all parts of India.
- Chrysanthemum: Pyrethrum, a commercial insecticide, is obtained from its inflorescence.
- Carthamus tinctorius: Red dye for dyeing silk and edible oil from seeds.
- Artemisia annua: Santonin drug from the flower used to remove worms from the body.
