Question: 116: Which one of the following plants shows vexillary aestivation and diadelphous stamens?
(1) Allium cepa
(2) Solanum nigrum
(3) Colchicum autumnale
(4) Pisum sativum
Answer: Option (4)
Explanation:
Vexillary aestivation is a characteristic arrangement of petals in which one large petal overlaps two lateral petals, which in turn overlap two smallest petals.
This type of aestivation is a typical feature of flowers belonging to the family Fabaceae.
Diadelphous stamens refer to an arrangement in which stamens are united into two bundles,
usually nine stamens forming one bundle and one stamen forming the other.
Pisum sativum (pea plant) belongs to the family Fabaceae and shows both vexillary aestivation
and diadelphous stamens.
Allium cepa and Colchicum autumnale are monocotyledonous plants and do not show these features.
Solanum nigrum belongs to the family Solanaceae and shows valvate aestivation
with epipetalous stamens, not diadelphous.
Therefore, the correct answer is Option (4).