My Neighbor Gave Me a Bag of These Strange Black Pods—Then I Found Out What They Were
When my neighbor handed me a plastic bag filled with these strange, black, horn-shaped things, I honestly had no idea what I was looking at.
They looked like little animal heads.
Some looked like bats.
Others looked like tiny buffalo horns.
And they were surprisingly hard.
Naturally, my first question was:
“What on earth are these—and am I actually supposed to eat them?”
It turns out they’re most likely water caltrops, particularly the two-horned variety known as Trapa bicornis. They’re also called water chestnuts, buffalo nuts, devil pods, ling nuts, or Jesuit nuts in different places. Despite the name “water chestnut,” they’re completely different from the crisp Chinese water chestnut commonly found in stir-fries. {“fallbackMarkdown”:”(Edible Plant Database)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:972,”end_idx”:1005,”safe_urls”:[“https://edibleplantdb.org/plants/10296/trapa-bicornis”,”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”,”https://en.wikipedia.org/wiki/Water_chestnut”,”https://en.wikipedia.org/wiki/Water_chestnut?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Edible Plant Database)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”Water caltrop (Trapa bicornis) — Edible Plant | Edible Plant Database”,”url”:”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”,”attribution”:”Edible Plant Database”,”pub_date”:null,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”Water chestnut”,”url”:”https://en.wikipedia.org/wiki/Water_chestnut?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”Wikipedia”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:0},{“turn_index”:0,”ref_type”:”search”,”ref_index”:22}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
And yes—there’s an edible part inside.
But there’s an important catch.
Don’t Eat Them Raw
The hard, black exterior isn’t what you eat.
Inside is a pale, starchy seed.
Although some sources describe water caltrops as edible raw, other references specifically warn that raw Trapa bicornis seeds contain harmful compounds and recommend cooking them before eating. There’s also a separate concern with freshwater-grown caltrops: raw or undercooked plants can carry parasites associated with contaminated water. {“fallbackMarkdown”:”(Edible Plant Database)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:1524,”end_idx”:1556,”safe_urls”:[“https://edibleplantdb.org/plants/10296/trapa-bicornis”,”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”,”https://www.sciencedirect.com/science/article/pii/S0924224416000169″,”https://www.sciencedirect.com/science/article/pii/S0924224416000169?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Edible Plant Database)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”Water caltrop (Trapa bicornis) — Edible Plant | Edible Plant Database”,”url”:”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”,”attribution”:”Edible Plant Database”,”pub_date”:null,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”Chemical composition, health effects, and uses of water caltrop – ScienceDirect”,”url”:”https://www.sciencedirect.com/science/article/pii/S0924224416000169?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”ScienceDirect”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:0},{“turn_index”:0,”ref_type”:”search”,”ref_index”:1}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
So if you have a bag like this sitting in your kitchen, don’t crack one open and eat it raw just to see what it tastes like.
So How Do You Eat Them?
The traditional preparation is surprisingly simple.
First, wash the pods thoroughly.
Then boil them while they’re still in their shells. Cooking times vary by source, but around 25–40 minutes is commonly recommended. The shell won’t necessarily look dramatically different when they’re finished, so don’t rely on appearance alone. {“fallbackMarkdown”:”(Chowhound)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:2053,”end_idx”:2086,”safe_urls”:[“https://clovegarden.com/ingred/my_wcaltz.html”,”https://clovegarden.com/ingred/my_wcaltz.html?utm_source=chatgpt.com”,”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/”,”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Chowhound)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”What Are Water Caltrops And How Do You Cook With Them?”,”url”:”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”,”attribution”:”Chowhound”,”pub_date”:1733356800,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”Water Caltrop”,”url”:”https://clovegarden.com/ingred/my_wcaltz.html?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”Clovegarden”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:3},{“turn_index”:0,”ref_type”:”search”,”ref_index”:11}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
After cooking, let them cool enough to handle.
Then crack open the tough shell and remove the white, starchy kernel inside.
A nutcracker is a much better idea than trying to break the shell with your teeth—the horns are extremely hard and awkward to handle. {“fallbackMarkdown”:”(Chowhound)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:2348,”end_idx”:2367,”safe_urls”:[“https://www.chowhound.com/1723352/what-are-water-caltrops-uses/”,”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Chowhound)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”What Are Water Caltrops And How Do You Cook With Them?”,”url”:”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”,”attribution”:”Chowhound”,”pub_date”:1733356800,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:3}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
The cooked kernel is often described as starchy, slightly crumbly and mildly nutty, with some people comparing the flavor to chestnuts. {“fallbackMarkdown”:”(Chowhound)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:2509,”end_idx”:2541,”safe_urls”:[“https://bcmapp.dev.i3.uconn.edu/plants/info/445″,”https://bcmapp.dev.i3.uconn.edu/plants/info/445?utm_source=chatgpt.com”,”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/”,”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Chowhound)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”What Are Water Caltrops And How Do You Cook With Them?”,”url”:”https://www.chowhound.com/1723352/what-are-water-caltrops-uses/?utm_source=chatgpt.com”,”attribution”:”Chowhound”,”pub_date”:1733356800,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”Plant View”,”url”:”https://bcmapp.dev.i3.uconn.edu/plants/info/445?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”BCM App”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:3},{“turn_index”:0,”ref_type”:”search”,”ref_index”:5}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
You can eat the cooked kernels as a snack, or add them to rice, stir-fries and other dishes. They can also be dried and ground into flour. {“fallbackMarkdown”:”(ScienceDirect)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:2682,”end_idx”:2714,”safe_urls”:[“https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.14372″,”https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.14372?utm_source=chatgpt.com”,”https://www.sciencedirect.com/science/article/pii/S0924224416000169″,”https://www.sciencedirect.com/science/article/pii/S0924224416000169?utm_source=chatgpt.com”],”refs”:[],”alt”:”(ScienceDirect)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”Chemical composition, health effects, and uses of water caltrop – ScienceDirect”,”url”:”https://www.sciencedirect.com/science/article/pii/S0924224416000169?utm_source=chatgpt.com”,”attribution”:”ScienceDirect”,”pub_date”:null,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”International Biological Flora: Trapa natans‡ – Palm – 2024 – Journal of Ecology – Wiley Online Library”,”url”:”https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2745.14372?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”BES Journals”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:1},{“turn_index”:0,”ref_type”:”search”,”ref_index”:8}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
Why Do They Look So Strange?
The bizarre shape is actually a natural defense mechanism.
Water caltrops grow in freshwater environments, and their fruits develop those distinctive pointed horns. The mature fruits can become very dark—almost black—which makes the ones in this photograph look particularly unusual. {“fallbackMarkdown”:”(Edible Plant Database)”,”reference”:{“matched_text”:””,”prefix”:null,”start_idx”:3034,”end_idx”:3066,”safe_urls”:[“https://doi.org/10.1111/1365-2745.14372″,”https://doi.org/10.1111/1365-2745.14372?utm_source=chatgpt.com”,”https://edibleplantdb.org/plants/10296/trapa-bicornis”,”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”],”refs”:[],”alt”:”(Edible Plant Database)”,”prompt_text”:null,”type”:”grouped_webpages”,”error”:null,”style”:null,”items”:[{“title”:”Water caltrop (Trapa bicornis) — Edible Plant | Edible Plant Database”,”url”:”https://edibleplantdb.org/plants/10296/trapa-bicornis?utm_source=chatgpt.com”,”attribution”:”Edible Plant Database”,”pub_date”:null,”snippet”:””,”attribution_segments”:null,”supporting_websites”:[{“title”:”International Biological Flora: Trapa natans‡ – Palm – 2024 – Journal of Ecology – Wiley Online Library”,”url”:”https://doi.org/10.1111/1365-2745.14372?utm_source=chatgpt.com”,”pub_date”:null,”snippet”:””,”attribution”:”DOI”}],”refs”:[{“turn_index”:0,”ref_type”:”search”,”ref_index”:0},{“turn_index”:0,”ref_type”:”search”,”ref_index”:7}],”hue”:null,”attributions”:null}],”status”:”done”,”fallback_items”:null},”showLoginRequiredCard”:false}
In parts of Asia, they’re a traditional food and have been cultivated for centuries.
So what initially looks like a bag of mysterious little black creatures is actually an old-fashioned edible plant product.
Still, there’s one thing I’d do before cooking the entire bag:
Ask your neighbor exactly where they came from.
If they were purchased from a reputable food supplier or harvested from a known edible crop, that’s one thing. If they were randomly collected from a pond, ditch, or other questionable freshwater source, I’d be much more cautious.
And remember: the ordinary Chinese water chestnut you see in cans and stir-fries is a completely different plant.
So, if someone handed you this bag without explanation, what would you have guessed these strange little horned pods were?
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