iRiddle

Just came up with this on the spot =P. Can you guys guess it?

Those that dry, end up to die
Such a shame they couldn’t survive.
Those that live, offer to give
New life, a joining of two.
Combination of love, without a glove
Just natural life from above.
Those that are swallowed
Its nutrients will sure follow.
Those that end up on your face
Well that’s a disgrace
You shouldn’t be messing with it!
What am I?