Question

Gynostegium (fusion of anthers with stigma) and pollinia are present in the family
(a)Apocynaceae
(b)Asclepiadaceae
(c)Convolvulaceae
(d)Solanaceae or Cucurbitaceae

Answer 1

This family is commonly known as ‘milkweed family’. They have milky juice, flowers with five united petals, and pod-like fruits. Gynostegium is generally a complex structure formed by the fusion of the stamens, styles, and stigmatic surfaces.

Complete answer:
Gynostegium and pollinia are present in the Asclepiadaceae family. Examples of the Asclepiadaceae family are Calotropis procera, wax plant (Hoya), Cryptostegia grandiflora, etc.
The members of this family are mostly present in the tropical regions of the world. The androecium consists of five stamens. In stamen, the anthers are combined laterally and form a five-sided blunt code which is usually attached on the inside to the stigma head. The fusion of anthers with stigma forms gynostegium.
Pollinium is a condition in which the pollen grains of each half anther are associated in tetrads and found in a sac-like structure. This pollinium helps during pollination by sticking to visiting insect pollinators that carry them to other flowers to facilitate cross-pollination.
Characteristics of the Asclepiadaceae family:
-They are mostly erect herbs or woody climbers but some plants are succulent.
-They have simple, sub-sessile, and exstipulate leaves.
-The inflorescence is generally the cymose type in which the axis ends in a terminal flower.
-The flowers are generally found to be arranged in umbelliform cymes.
-In gynoecium, the ovaries are free, but styles fused to form a commonly swollen stigma-head.
-The anthers are generally sessile.
So, the correct answer is ‘Asclepiadaceae’.

Note: -Hoya is a plant of succulent habit that possesses fleshy stem and leaves.
-The flowers of the Asclepiadaceae family are Pedicellate, bracteate, hermaphrodite, actinomorphic, and regular.
-Gynostegium is not found in the subfamily Periplocoideae.