Question

Sunflower is not a flower. Explain.
NCERT Class XI
Biology - Exemplar Problems
Chapter 5. Morphology of Flowering Plants

Answer 1

Answer:

Sunflower is actually an inflorescence (capitulum), it is not a flower.

Capitulum (Head): Here the peduncle is flattened which is called receptacle. Inflorescence is surrounded by whorl of bracts collectively called involucre. On receptacle two kinds of florets are present: .

1. Ray florets: Zygomorphic, unisexual female, corolla ligulate or strap shaped.

2. Disc florets: Actinomorphc, bisexual, corolla tubular, present in centre. Ray florets present towards periphery and disc florets present in the centre, e.g.: Compositae (Asteraceae) family-Sunflower (Helianthus), Tagetus (Marigold) and Dahlia.