Differentiate between:
$(a)$ Bract and Bracteole
$(b)$ Pulvinus and Petiole
$(c)$ Pedicel and Peduncle
$(d)$ Spike and Spadix
$(e)$ Stamen and Staminode
$(f)$ Pollen and Pollinium

(N/A) Bract: It is a leaf-like structure in whose axil a flower is produced. They can be small,scaly,green,or colored; generally,they are single.
$\rightarrow$ Bracteole: It is a small,bract-like structure produced on the pedicel of a flower.
$(b)$ Pulvinus: It is the swollen base of the leaf stalk (petiole) found in many legumes,which helps in leaf movement.
$\rightarrow$ Petiole: It is a cylindrical or semi-cylindrical stalk-like structure that connects the leaf base to the leaf lamina.
$(c)$ Pedicel: The stalk of an individual flower is called a pedicel.
$\rightarrow$ Peduncle: The main axis of an inflorescence that bears flowers is called a peduncle.
$(d)$ Spike: An inflorescence with sessile (stalkless) flowers arranged on an elongated axis,e.g.,$Achyranthus$.
$\rightarrow$ Spadix: An inflorescence where the axis is fleshy and bears sessile unisexual flowers. The female flowers are at the base,and male flowers are above them. The entire axis is often protected by a large bract called a spathe,e.g.,$Colocasia$,banana.
$(e)$ Stamen: The male reproductive organ of a flower,consisting of a filament and an anther.
$\rightarrow$ Staminode: $A$ sterile or non-functional stamen is called a staminode.
$(f)$ Pollen: The microspores produced in the anther of angiosperms are known as pollen grains.
$\rightarrow$ Pollinium: $A$ coherent mass of pollen grains found in the anther of certain plants like $Calotropis$.