Non-functional stamens are called _______________
A) Accessory stamens
B) Staminode
C) Supplementary stamens
D) Staminates

Hint: Androecium: Third whorl, inner to corolla. It is male reproductive system composed of stamens. A stamen Consists of anther connective and filament. Anthers are bilobed. Each lobe contains two microsporangia or pollen sacs. Pollens are produced in pollen sacs. There may be variation in the length of filaments within flowers as in Salvia and Mustard.

Complete answer:
Accessory stamens :- the accessory structures are those structures which do not have any role in reproduction. But stamens have the most important role in reproduction. Thus stamens can’t be an accessory. Hence this option is not correct.
Staminode :- the stamen which do not produce pollen grains is known as sterile stamen. These stamens are non-functional. The sterile stamen is either known as abortive stamen or staminode. Hence this option is correct.
Supplementary stamens :- stamens can’t be supplementary as these are essential parts. This part of the flower can not be replaced by any another structure. Hence this option is also not correct.
Staminates :- the flowers which have stamen that are reproductive and not sterile. But the flower has no pistil and is called as staminates. Hence this option is not correct.

Our required answer is b that is staminode.


Note: Stamen of a flower may be united or free. Stamen is the reproductive structure of male. It consists of a stalk, or filament and an anther. Sterile stamens are usually known as staminode. When stamens get attached to petals, they are called epipetalous.