Answer:
It cannot be seen, it weighs nothing, but when put into a barrel, it makes it lighter.
What measures out time until in time all is smashed to it?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.
It is sometimes known to have silver linings.
Hold these between your knees if you want to set a Cuban beat.
What did the baby corn say to its mother?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?