Bottle gourd is a vine grown for its fruit, which can be either harvested young to be consumed as a vegetable, or harvested mature to be dried and used as a utensil. When it is fresh, the fruit has a light green smooth skin and white flesh.. Its fruits have a variety of shapes: they can be huge and rounded, small and bottle shaped, or slim and serpentine, and they can grow to be over a metre long. Rounder varieties are typically called calabash gourds.