raphide
/ˈreɪfaɪd/
noun
- A needle-shaped crystal of calcium oxalate found in many plant cells, which can cause irritation if eaten.
- Under the microscope, the raphides looked like tiny needles inside the plant tissue.
- The sharp raphides in raw taro can irritate your mouth if the vegetable isn't cooked properly.
- Many houseplants contain raphides that cause a burning sensation when chewed.