Asteraceae Compositae the Sunflower Family Taxonomic Position Kingdom

Asteraceae (Compositae) - the Sunflower Family

Taxonomic Position: Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Subclass: Asteridae Order: Asterales Family: Asterceae

Distribution • Second largest family in the angiosperm • More than 900 genera and 15000 species • More than 10% of flowering plants

Identifying Characters • • • Plant mostly herb, some are climbers Leaves usually exstipulate Involecre bract present Ray and disc floret present Calyx reduce to papus or scales Stamens epipataloiou with syngenessus anther Ovary inferior, bicarpellary syncarpous, unilocular Basal Placentation Fruit cypsela

Morphological Features Root: Usually tap roots but root tubers also found Stem: Erect or prostate, rarely climbing, some time woody Leaf: Simple some time compound Flower: Inflorescence head or capitulate Two types- Ray floret and disc floret Ray floret-Present in the perifery, zygomorphic, ligulate, unisexual female flowers • Disc floret: Central position, bisexual, actinomorphic • Calyx: Modified into papus or scale leaf • Corolla: Petal 5 or three tubular in disc florets or ligulate in ray florets, gamopetalous, aestivation valvate. • • •

Morphological features • Androecium: Stamen five, syngenesious, epipetalous • Gynoecium: Bicarpellary syncarpous, ovary inferior with single locule, Sigma two and bifid • Fruit: Indehiscent cypsela

Economical Importance • Ornamental • Edible and medicinal oils • Medicine and insecticides