Those bottle gourds (also known as calabash), that are cultivated for food, are usually longish and cylindrical in shape without the indented near the center. It is mainly used as a vegetable and can be quite tasteless, bitter or slightly sweet on its own. Its usages is so versatile that it can even be used as musical instrument, pipes or anything you can think of. Some of the shapes are so unnatural as it can be forced-grown in earthen molds or constricted by bands, to form whatever shapes the grower intended for.
The calabash was one of the first cultivated plants in the world, grown not primarily for food, but for use as a water container. The bottle gourd may have been carried from Africa to Asia, Europe and the Americas in the course of human migration.
Found these at a farm, growing abundantly and in a beautiful green!