Question

Diadelphous stamens are found in
A)Ranunculaceae
B)Fabaceae
C)Poaceae
D)Malvaceae

Answer 1

Hint: Stamen consists of a filament and a pollen-bearing anther at its tip. When stamens are fused together by filaments in order that they form two separate bundles, or a bundle and a lone separate stamen is thought as diadelphous stamens.

Complete answer:
Ranunculaceae: Herbs, leaves exstipulate, incised blades, hypogynous flowers, spiral or spirocyclic; sepals often deciduous, petaloid; calyx and corolla free; indefinite stamens, free; carpels polycarpellary, apocarpous; fruit aggregate.

1)Perennial habit
2)Presence of stipules
3)Leaves with reticulate venation
4)Flowers hermaphrodite
5)Actinomorphic symmetry
6)Large number of petals
7)Calyx and corolla free
8)Gynoecium polycarpellary and apocarpous

Fabaceae-Papilionaceae: The family includes 600 genera and 1200 spices. It's the second largest family of dicotyledons.

1)Leaves alternate, stipulate
2)Flowers hermaphrodite
3)Corolla polypetalous
4)Androecium polyandrous
5)Ovules anatropous
6)Plants herbaceous, annual
7)Leaves compound and in some modified into tendrils
8)Flowers zygomorphic

Poaceae: Herbs with joint stem, leaves simple, alternate, sheath open, ligulate; inflorescence compound spike; flowers zygomorphic, hypogynous, protected by palea; perianth represented by minute scales; stamens 3, versatile; carpel one, style 2 or 3, stigmas feathery, basal placentation; fruit caryopsis; testa fused with pericarp.

Malvaceae: Stellate hairs on young parts, alternate leaves, stipulate, multicostate reticulate; inflorescence solitary or cyme; actinomorphic flower, hermaphrodite, hypogynous, pentamerous, with epicalyx, calyx free or united, corolla free; stamens indefinite, monadelphous; anthers monothecous, stamens united to make a tube; syncarpous, ovary multilocular, superior, axile placentation; fruit schizocarpic carcerulus or capsule.

Hence, the correct answer is option (B)

Note: Union of stamens involves adhesion or cohesion. When stamens adhere to petals they're termed epipetalous. When this adherence is to perianth leaves it is epiphyllous. Cohesion involves either only filaments (adelphi) or only anthers (syngeny). If all the stamens unite by their filaments forming one bundle of stamens with all anthers free it is a monadelphous condition. Oxalis (Oxalidaceae) have few unequal stamens. In diadelphous stamens form one bundle.