Practice question

Capitulum of Helianthus annuus comprises outer showy ray florets and central disc florets with distinct sexuality. Ray florets are zygomorphic, ligulate, adapted for pollinator attraction, generally pistillate with reduced or absent androecium or completely neutral lacking both androecium and gynoecium. They often lack functional stamens allocating resources to display. Bisexual fertile disc florets produce cypsela fruits after fertilization. Staminate ray condition is rare in composites. Distinction between ray pistillate or sterile and disc bisexual underlies heterogamous adaptation for cross-pollination and increased reproductive success in family Asteraceae.