Distribution of Asteraceae:
The family is commonly known as Sunflower family. It is the largest family of dicotyledons, comprising 950 genera and 20,000 species, out of which 697 species occur in India. They are worldwide in distribution and abundant in tropics and in cold arctic or alpines regions.
Economic Importance of Asteraceae:
- Food: Leaves of Lactuca sativa are used as salad. The roots of Helianthus tuberosus are edible.
- Oil: The seeds of Helianthus and Artemisia yield oil.
- Medicinal: Solidago used in dropsy. Artemisia yields santonin which is used as vermifuge. The roots of Taraxacum used in bowel disorders. The juice of Emillia sonchifolia leaves has cooling effect and is used in eye inflammation and also for night blindness. Eclipta alba used as tonic in spleen enlargement. Centipeda orbicularis is used in cold and toothache.
- Rubber: It is obtained from Solidago laevenworthii and Taraxacum.
- Insecticide: The capitula of Chrysanthemum roseum and C. cinerriefolium are dried, powdered and used as insecticide.
- Ornamental: Zinnia, Dahila, Cosmos, Chrysanthemum, Calendula, Helichrysium, Aster Helianthus etc. are well known garden plants.
- Weeds: Xanthium, Blumea, Sonchus, Vernonia are the common weeds.
Affinities of Asteraceae:
Taxonomists have assigned different systematic position to the family. Bentham and Hooker placed the family under Gamopetalae just after Rubiales. Hutchinson did not treat the family as the last evolved and put the Asterales under the 6th series far before the last series Laminales; but he placed it near Rubiaceae. Engler and Rendle placed it as the highest evolved dicot family.