Ridge gourd genus of tropical and subtropical vines in the cucumber (Cucurbitaceae) family. It is also known as luffa. In everyday non-technical usage, the luffa, also spelled loofah (referred to as gilki or ram tori in India), usually means the fruit of the two species L. aegyptiaca and L. 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. The vegetable is popular in India, China, Vietnam. When the fruit is fully ripened, it is very fibrous. Various dishes of gilki are prepared in India and eaten. 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. The name luffa was taken by European botanists in the 17th century from the Egyptian Arabic name. It is simple but very popular vegetable usually made with a plentiful tomato gravy and garnished with green chillies and fresh coriander.