Question

why are papaya and date palm plants are said to be dioecious whereas cucurbits and coconut palms monoecious inspite of all of them bearing unisexual flowers

Answer 1

Papaya and date palm plants are said to be dioecious , because these plants bears exclusively either male flowers or female flowers. Cucurbits and coconut palms are said to be monoecious, because both male and female flowers are borne on the same plant.

Answer 2

Monoecious or homothallic plants are those where male and female flowers are present on the same plant.

Dioecious or heterothallic plants are those where male and female flowers are present on separate plant bodies. Papaya, date palm, cucurbits, and coconut palm although contain unisexual flowers, papaya or a date palm tree contain either only male flowers or only female flowers.

On the other hand, cucurbits and coconut palm contain both the male and female flowers on the same plant.