Name: Apomixis and Polyembryony
Uploaded: 2019-07-19
Duration: 7 min 23 s
Description: Apomixis and polyembryony are unusual forms of reproduction that allow seed formation, for continuity of life, without genetic shuffling. Do you want to know...

Question

What is entomophily? Write about the characteristic features of entomophilous flowers.

Accepted Answer

When pollination occurs by means of insects then it is called entomophily and the flowers are called entomophilous flower. The brightly coloured showy flowers possessing nectar attract insects for pollination. Examples: Sunflower, Marigold, etc.

Characteristic features of insect-pollinated flowers:
Flowers: The entomophilous flowers are larger in shape, brightly coloured and showy so that they can attract insects. The coloured petals serve as a flag apparatus for attracting insects like a butterfly, moth, bees, etc. If the insect-pollinated flowers are smaller, then they remain in groups to form an inflorescence, e.g., capitulum inflorescence of Sunflower, Marigold, etc. In the case of Mussaenda, the petals of the corolla through yellow coloured are smaller. Hence, in their case, petal-like sepals are larger and white, pink or red coloured, so that they can attract insects easily. The flowers of Bougainvillea are smaller and dull in lustre, but their petal-like bracts become red or pink or white or yellow coloured for attracting insects.

Smell: Those flowers which bloom at night emit a sweet scent to attract insects, e.g., Jasmine, Cestrum (B. Hasnahana). Nyctanthes (B. Sheoli), etc. Nocturnal flowers are mostly white coloured hence the sweet smell of flowers attract insects.
The sitting arrangement of insects: Most of the insect-pollinated flowers may have special sitting arrangements, so that they can visit the flowers and can eat the nectar or spores without any difficulty, e.g., the standard of Crotalaria (B. Aparajita), Sesbania (B. Bak), the lower lip of Salvia. The pollinia of orchids also act as a special device for insect pollination.

Nectar: The honey glands, nectar glands, situated at the base of petals or sepals, secreting sweet-scented fluid, is a characteristic feature for entomophilous flowers.
Pollen grains: Pollen grains are larger, and the surface becomes rough, spiny, sticky so that they can stick to the body of an insect easily. Pollen grains of many entomophilous flowers are very sweet to taste.
Stigma: The stigmatic surface is rough and sticky so that the pollen grains stick to it firmly.

What is entomophily? Write about the characteristic features of entomophilous flowers.

Important Questions on Sexual Reproduction in Flowering Plants

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