Receiving fresh produce from a neighbor’s garden is one of the simple pleasures of the growing season. Sometimes it’s easy to recognize the gift, such as tomatoes, cucumbers, or herbs, but other times you’re handed something completely unfamiliar. Unusual fruits, vegetables, and edible plants often leave people wondering what they are, whether they’re safe to eat, and how they should be prepared.

Many home gardeners grow varieties that aren’t commonly sold in grocery stores, including heirloom vegetables and regional specialties. When harvest season arrives, they often have more produce than they can use, so they share their extra crops with friends and neighbors. While these gifts are generous, they can also be puzzling if you’ve never encountered the item before.

If the bag contains dark brown or black pods with two sharp, horn-like points, you’ve likely been given water caltrops. Also known as buffalo nuts, bat nuts, or singhara in some parts of the world, these edible seeds come from an aquatic plant that grows in ponds, lakes, and other calm freshwater environments. Although they’re sometimes confused with the sliced water chestnuts commonly found in stir-fries, water caltrops come from a completely different plant and have a distinctive appearance.

Water caltrops are typically boiled or roasted before eating, as the hard outer shell protects a starchy, slightly sweet kernel inside. Once cooked, the shell can be cracked open to reveal the edible seed, which has a texture similar to chestnuts or potatoes. They can be enjoyed as a snack, added to soups and stews, or used in a variety of traditional recipes, making them a unique and nutritious gift from the garden.