Question

Butterfly shaped flower with one stranded, two wing like two keeled petal belongs to
A. Compositae
B. Rubiaceae
C. Malvaceae
D. Papilionaceae

Answer 1

Hint: Dicotyledonous plants, distinguished by their butterfly-shaped flowers, made up of a regular top petal, followed on the sides by two opposing petals, the wings, followed by a keel, the bottom petal, in which the reproductive organs are located.

Complete Answer:
- Papilionaceous flowers are flowers found in many, but not all, plants of the species-rich Faboideae subfamily of legumes with the distinctive irregular and butterfly-like corolla.
- With a corolla consisting of five petals, the flowers have a bilateral symmetry. The banner (also vexillum or standard petal) is recognised as a single, wide, upper petal. Two equal and smaller lateral wings (or alae) are embraced and compressed by the semi cylindrical base of the banner.
- A pair of small keel petals, which are much lower than the wings, but are within them, are enclosed by the wings in turn.
- They have concave sides and they conform to the wings' shape. At their bases, the two keel petals are fused or stuck together to form a boat-shaped structure that encloses the vital organs of the flower, namely androecium and gynoecium.
- These flowers usually have a vexillary aestivation (i.e. descendingly imbricating or overlapping).
- The stamens also have a diadelphous morphology, meaning that in each set they are united in two sets with a different filament type. A membranous sheath at its root, which envelops the single, superior pistil in a tube, forms the inferior set.
- The tube is divided into nine filaments which trace the base of the petals of the keel that enclose them. Above them lies the single free filament.

The correct Answer is option (D) Papilionaceae.

Note: Nuts, peas, sweet peas, alfalfa (lucerne), clovers, lupines, smoke trees, black locusts, locoweeds and coral trees are well-known plant genera in the Faboideae that exhibit this corolla morphology. The coral trees' flowers are diadelphous and are considered papilionaceous, but the wings are much smaller, suggesting a three-petalled flower. To promote pollination by some bird classes, their keel petals are elongated, fused together and sometimes tubular, while secondary compounds in their nectar seem to repel bees.