Vietnamese coriander vs Coriander leaf
The short answer
Sold as "Vietnamese coriander" and not a coriander. Coriander leaf is Coriandrum sativum, of the carrot family; rau răm is Persicaria odorata, a knotweed, with narrow, dark-marked leaves that survive heat far better. Both carry the soapy-citrus aldehyde note that divides people, which is where the name comes from — but rau răm adds a peppery, almost medicinal bite that coriander lacks. In a laksa or a Vietnamese salad, coriander gives the right family of flavour and loses the edge; in a salsa, rau răm is too sharp.
Side by side
| Vietnamese coriander | Coriander leaf | |
|---|---|---|
| Botanical identity | Persicaria odorata (Lour.) Soják | Coriandrum sativum L. |
| Part used | leaf | leaf |
| Origin | Mainland Southeast Asia — Vietnam and its neighbours — where it grows wild and semi-wild along ditches and paddy margins. | The eastern Mediterranean and western Asia, where the species has been cultivated for several thousand years. |
| Flavour notes | coriander-like, peppery, citric, waxy, sharp | citric, green, cooling, sappy, soapy to some |
| Heat | Scoville does not apply | Scoville does not apply |
| Flavour | Hot-peppery and coriander-like, with a faint tongue-prickling bite and a slightly astringent finish. Eaten raw, it cuts through fat and richness — the reason it is served with duck, eggs and coconut broths. | Bright, citric and cooling, with a soapy or metallic edge that some people barely register and others cannot get past. It cuts through fat, chilli and richness better than almost anything else, which is why it is used at the end of dishes from Mexico to Vietnam. |
| Aroma | Coriander-like and sharper: green, soapy-citrus, with a waxy, almost metallic high note. Where coriander is soft, rau răm is pointed. | Powerful, citric and unmistakable, with a green sappy quality underneath. It is one of very few herbs strong enough to identify a cuisine from across a room, and one of very few that a large minority of people actively dislike. |
Can you swap them?
Substitution is directional: the answer is often different in each direction, and both are recorded.
Coriander leaf with Mint
AcceptableCoriander leaf supplies the shared aldehyde smell and a few mint leaves some of the sharpness, and together they read as a herb garnish of the right kind. What is lost is the peppery bite and the waxy, pointed quality that makes rau răm cut through a rich broth.
| Flavour | Aroma | Colour | Heat |
|---|---|---|---|
| partial | close | close | less |
Works for
- Laksa garnish, where it is one herb of several
- Vietnamese chicken salad
- A herb plate for rolls and soups
Does not work for
- Penang asam laksa as its signature herb, where the difference is noticeable
- Anything simmered for more than a minute or two — coriander leaf collapses faster
Cuisine: Keeps the dish recognisably Southeast Asian while losing a note that people who know it will miss.
Which should you buy?
Vietnamese coriander
Fresh, always, and a pot rather than a bunch if you use it often: the stems root in a glass of water and the plant grows fast in warmth. Dried rau răm is barely worth buying, because the dishes it belongs in eat it raw.
Coriander leaf
This is the one profile on SpiceHQ where the buying advice is to skip a form entirely. Dried coriander leaf keeps almost nothing of what makes the herb worth having, and a dish built on its citric lift is better made with a different herb than with a dried version of the right one. Buy fresh, use the stems as well as the leaves, freeze the roots if you find a bunch that has them, and treat the jar of green flakes in the supermarket as a colouring rather than a seasoning.
Full detail on vietnamese coriander and coriander leaf, including evidence grades and sources for every claim above.