They're also one of the reasons you shouldn't handle a large pile carelessly.

If the fruits are particularly sharp or have broken points, use caution when washing, moving, or opening them.

A towel or kitchen glove can provide additional protection while handling the hard shells.

How to Store Them

Fresh water caltrops should be handled similarly to other perishable plant foods.

If they are intended for consumption, keep them clean and appropriately refrigerated according to local food-safety guidance.

Avoid eating fruits that have:

And don't assume that cooking will make spoiled food safe.

Cooking can reduce many microorganisms, but it doesn't magically reverse spoilage or eliminate every food-safety hazard.

What If You Don't Know Where They Came From?

This is especially important in the situation shown in the photograph.

The caption says:

"My neighbor gave me a bag of these. Anyone know what they are? How do you eat them?"

That's a perfectly reasonable question.

But before eating them, the person should ideally ask the neighbor:

Where were they harvested?

If the neighbor bought them from a market or food supplier, that's useful information.

If they came from a pond, lake, or wild waterway, additional caution is warranted.

If they were collected from an unknown body of water, it's better to establish their identity and food-safety status before consuming them.

This is another important consideration.

The photograph strongly resembles water caltrops, but photographs aren't always enough for definitive botanical identification.

There are multiple species and varieties, and common names can vary dramatically between regions.

If someone plans to eat a wild or unfamiliar plant, identification should ideally be confirmed using:

Never rely solely on a social-media comment saying, "Yes, that's edible."

Part of the fascination comes from their appearance.

Modern supermarkets have made many foods look predictable.