In everyday non-technical usage, the luffa, also spelled loofah, usually means the fruit of the two species Luffa cylindrica [syn. Luffa aegyptiaca] and Luffa acutangula. The fruit of these species is cultivated and eaten as a vegetable. The fruit must be harvested at a young stage of development to be edible. When the fruit is fully ripened, it is very fibrous. The fully developed fruit is the source of the loofah scrubbing sponge which is used in bathrooms and kitchens. Luffa are not frost-hardy, and require 150 to 200 warm days to mature.
^ Meet some pollinators 🙂
The fruit section of Luffa cylindrica may be allowed to mature and used as a bath or kitchen sponge after being processed to remove everything but the network of xylem fibers. If the loofah is allowed to fully ripen and then dry out on the vine, the flesh disappears leaving only the fibrous skeleton and seeds, which can be easily shaken out. Marketed as luffa or loofah, the sponge is used as a body scrub.