Question

Papilionaceous corolla occurs in
A. Brassicaceae
B. Asteraceae
C. Fabaceae
D. Poaceae

Answer 1

Hint:-Papilionaceous corolla is the unique type of aestivation found in the Papilionaceae family in which there are five petals, the largest petal known as regular or vexillum overlapping the two wings known as lateral petals, which in turn overlap two of the smallest anterior petals known as keels.

Complete Answer:-Papilionaceous flowers are flowers occurring in many, but not all, plants of the species-rich Faboideae subfamily of legumes with the distinctive irregular and butterfly-like corolla. Tournefort proposed that Valerius Cordus, who applied it to the bean flowers, emerged with the term Flores papilionaceae.
In papilionaceous flowers, which are respectively known as explosive, valvular, piston and brush mechanisms, four distinct pollen release mechanisms are known. Both pollen is released automatically as strain is permanently released (usually by an insect) on the staminal column in the explosive or tripping process, allowing it to snap against the normal petal.
When pollinators unseal the upper rim of the keel petals and push them inward, pollen is released repeatedly through the valve system. When the keel tip is pushed by an insect to expel pollen into a hole in the tip, pollen is released repeatedly through the piston system. In order to prevent self-pollination, the brush system uses a pistil that is longer than the stamens.
Nuts, peas, sweet peas, alfalfa, clovers, lupines, smoke trees, black locusts, locoweeds and coral trees are well-known plant genera in the Faboideae that display 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 facilitate pollination by certain bird groups, their keel petals are elongated, fused together and sometimes tubular, while secondary compounds in their nectar seem to repel bees.

From these discussions we can conclude that Papilionaceous corolla occurs in the Fabaceae family.

Therefore the correct answer is option (C).

Note:- While belonging to the Faboideae, the false indigo genus does not exhibit the morphology of the papilionaceous corolla, since it has only one petal per flower, namely the banner. The clover corolla appears to be monopetalous, since all five petals are mostly joined to form a tube below.