Question

the flower without petals

Answer 1

cactus flower have flowe with our patel

Answer 2

Hi,
Here is the answer to your query:-

(a) Cyathium inflorescence is found in some members of Euphorbiaceae (milk weed)family, it consists of a central female flower surrounded by many male flowers, all these flowers are without sepals and petals, unisexual flower is represented by single member of the reproductive whorl.

(b) Some Croton species (Euphorbiaceae)
Croton humilis: female flowers.

Thanks
@SHIVAM