Identify the aestivation in which every perianth lobe has one margin overlapped and one margin underlapped. 

detailed solution

Correct option is C

In twisted aestivation every perianth lobe of a whorl has one margin inside and one margin outside. In valvate aestivation neither of the margins of perianth lobes are overlapped or underlapped. In Imbricate aestivation, one perianth lobe is outside, one inside and the remaining three have one margin inside and one margin outside. In Vexillary aestivation, one perianth lobe is outside, two lateral perianth lobes have one margin inside and one margin outside, two perianth lobes are fused and inside.