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Sub-class : Gamopetalae Series : Inferae Order : Asterales Family : Asteraceae
Diagnostic Characters
Most plants show herbaceous habit. Flowers are aggregated together in dense heads surrounded by the involucral bracts, which make them very conspicuous and attractive. Floral parts are completely whorled and typically pentamerous. Sepals get reduced to pappus. Carpel is inferior. Flower buds are well protected by involucral bracts. Commonly known as daisy family or sunflower family. This is the largest family of the flowering plants.
Diagnostic Characters
Corolla tube is short enough to enable the nectar to be reached by insects. Fruits are very light due to the presence of hairy pappus.
Common plants
Helianthus annuus Cichorium intybus Tridax procumbens Calendula officinalis Stem :- Stem tubers are produced in Helianthus tuberosus and Crepis bulbosa. The stem is leaf like in Baccharis. Stem is slender, covered by different types of trichomes.
Gynoecium :- Bicarpellary, syncarpous, inferior, unilocular, with single anatropous ovule, style is simple and stigma bifid. Ray florets : These are zygomorphic, pistillate (female) or neuter, ligulate and epigynous. Calyx : Like disc florets, pappus. Corolla : Consists of 5 petals, gamopetalous strap shaped (ligulate). Gynoecium : Bicarpellary, syncarpous, ovary inferior, unilocular with single anatropous ovule. Fruit :- Cypsela, often crowned by persistent pappus. Seeds :- Non-endospermic ; embryo straight with inferior radicle.
