Morphology of Flowering Plants — BIOLOGY STD 11 Science — Question

Sunflower is not a single flower rather it represents a complete inflorescence, called capitulum or racemose head. Small sessile flowers called florets develop compactly over discoid peduncle. They open in centripetal order. They are surrounded and protected by an involucre of bracts. The florets are of two types namely, ray florets and disc florets. Ray florets are usually female and zygomorphic and disc florets are bisexual and actionomorphic. In Helianthus, the ray florets are towards the periphery and disc florets are at the centre of the inflorescence.