Persicaria odorata is a species of flowering plant in the knotweed family, Polygonaceae. It is sometimes referred to by the common names Vietnamese coriander, rau răm (from Vietnamese), laksa leaf (calque from Malay daun laksa), Vietnamese cilantro, phak phai (from Thai: ผักแพว), praew leaf, hot mint, Cambodian mint and Vietnamese mint, is an herb whose leaves are used in Southeast Asian and Northeast Indian cooking.

But despite its other name, Vietnamese coriander is unrelated to the mints, nor is it in the mint family Lamiaceae, but its general appearance and fragrance are reminiscent of them. It is also not closely related to coriander (family Apiaceae). Persicaria is in the family Polygonaceae, collectively known as "smartweeds" or "pinkweeds". The similarities in the tastes and smells between Persicaria and coriander and mint may be an example of convergent evolution.

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