"The cylindrical bathroom sponges known as loofah can be eaten when young. They are the fruit of a tropical relative of the marrow, Luffa cylindrical, and have nothing to do with the sea. Young cooked fruits taste something like marrow. To make bathroom loofahs, the ripe fruits are immersed in running water until the outer wall disintegrates, and the fibrous remains are then cleaned and bleached.
Loofahs have also been used as filters in steam and diesel engines, in mats, shoe soles and gloves, and as padding in the steel helmets used before the Second World War by the US Army."
Source: "Reader’s Digest Book Of Facts"
Loofah is a climbing vine and belong to the same family as a cucumber. This is why it looks like a massive cucumber while growing. Loofah needs warm dry climates, and is sensitive to frost.
"The plant family Cucurbitaceae consists of various squashes, melons, and gourds, including crops such as cucumber, pumpkins, loofahs, calabash, and watermelons. The family is predominantly distributed around the tropics, where those with edible fruits were amongst the earliest cultivated plants in both the Old and New Worlds.
The Cucurbitaceae are an important family consisting of approximately 125 genera and 960 species, mainly in regions tropical and subtropical. All species are sensitive to frost. Most of the plants in this family are annual vines but there are also woody lianas, thorny shrubs, and trees (Dendrosicyos). Many species have large yellow or white flowers (Loofahs flowers are yellow). The stems are hairy and pentangular."
When the loofahs are left long enough on the vine, the outer green cover dries and turns brown. The loofahs then are ready for harvesting and the dried brown cover can be peeled completely.
This is the final product.
loo.fah n. Also chiefly U.S. loo.fa, luf.fa.
1. The dried, fibrous, spongelike interior of the fruit of the dishcloth gourd, used as a washing sponge or as a filter.
2. The dishcloth gourd:
- Any of several tropical vines of the genus Luffa; especially, Luffa cylindrica, cultivated for its cucumber-like fruits.
- The fruit of any of these plants, the fibrous skeleton of which is used as a loofah.
Also called "vegetable sponge".
Source: "Reader's Digest Universal Dictionary"
1.the fibrous matter of the fluid-transport system of a marrow-like fruit, which is dried and used as a bath sponge.
2.the tropical Old World climbing plant of the gourd family which produces loofahs, which are also edible.
Luffa cylindrica, family Cucurbitaceae
late 19th century: from Egyptian Arabic lūfa, denoting the plant.
Source: "Oxford Dictionary"