Luffa
The Luffa (also rendered "Loofah" as an alternative translation of the Arabic) is a type of Cucurbit grown either for food or for the fibrous skeleton of its fruit.
Uses and varieties
Luffa acutangula, the winged Luffa or ridged Luffa, is eaten immature as a vegetable in hot (preferably tropical) climates.
Luffa aegyptiaca can also be eaten if very immature. This one is better known for being allowed to over-ripen and rot, then cleaned to free up a stiff, fibrous, sponge-like network used like a sponge for bathing, cleaning, and scouring.
For further reading
Luffa info website