At first glance, these dark, horn-shaped objects may look like something from another world. They are actually water caltrops, also known as bat nuts, devil pods, or buffalo nuts. They are the hard fruits of aquatic plants in the Trapa family and are especially recognizable because of their unusual, pointed shapes.
The outside of a water caltrop is dark, woody, and extremely hard, with sharp projections that can resemble little horns or animal shapes. Inside, however, is a completely different sight: a white, starchy kernel. Its flavor is often compared to chestnuts, sweet potatoes, or mild water chestnuts.
Although they may look like nuts, water caltrops are technically fruits. They have been eaten for centuries in parts of Asia, where they are valued as a starchy food. Their unusual appearance can make them seem intimidating, but the edible portion is found inside the tough outer shell.
If you come across water caltrops, they should be cooked thoroughly rather than eaten raw. One traditional method is boiling them for roughly 20–30 minutes. After cooking and allowing them to cool slightly, the hard shell can be carefully cracked open using a suitable tool, revealing the soft white kernel inside.
What looks like a strange natural object is therefore a surprisingly familiar type of food. Water caltrops combine an unusual appearance with an edible, mildly sweet and starchy interior. Their shape may make them look mysterious, but once prepared properly, they can be a fascinating food with a long culinary history.