Bath sponge that's really a tropical gourd
It resembles a cucumber, but unlike that vegetable, luffa's gourdlike... [DOC] [TLE] sponge gourd - Memidex dictionary/thesaurus [PAR] "sponge gourd" definition: any of several tropical annual climbers having large 
yellow flowers and ... for the mature fruit's dried fibrous interior that is used as a 
sponge ... system of a marrow-like fruit, which is dried and used as a bath sponge
.