Question

.................. is known as incomplete because, in this subclass, sepals and petals are not distinct. Flowers usually possess only one whorl of perianth which is sepaloid.

• A. Polypetalae
• B. Gamopetalae
• C. Monochlamydeae
  
• D. Both A and B

Answer 1

Answer: (C)

Monochlamydeae

Monochlamydeae is a group of archichlamydeous dicotyledonous plants and includes the families Salicaceae, Betulaceae, Fagaceae, Ulmaceae, Moraceae and Cannabaceae. As per Bentham and Hooker's system of classification, dicotyledons are classified into 3 sub-classes based on the nature of perianth, presence of perianth whorls, petaloid and sepaloid petals, presence or absence of perianth lobes. Monochlamydeae is the subclass with perianth in one or two whorls, sepaloid or rarely absent.
Therefore, the correct answer is option C.