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Finger grass (Rice paddy herb, Limnophila aromatica)

Plant family

Scrophulariaceae (figwort family, snapdragon family)

Botanical synonyms



Several species of Limnophila are found in silent waters Southeast Asia; some of them are common aquarium plants in the West. In Vietnam, rice paddy herb is mostly cultivated in flooded rice fields.

A related species, Limnophila rugosa (Roth) Merril (syn. L. roxburghii, Herpestris rugosa Roth) has anis-scented leaves; it is used for culinary purposes only occasionally (Jawa)

Used plant part

Fresh leaves.

Sensoric quality

This herb has a unique flavour difficult to describe. It is definitely lemony, with a certain tickling quality.

Main constituents

The leaves contain about 0.13% essential oil, whose main components are limonene and perillaldehyd.

Rice paddy herb with flower


Rice paddy herb is one of the many culinary herbs used only or predominantly in Vietnamese cuisine.

The intense, almost sparkling lemon odour of this plant harmonizes almost perfectly with fresh water fish. In the South of Vietnam, it is mandatory for spicy fish soups (canh chua); the herb is not cooked, but served raw and coarsely chopped as part of the herb garnish that accompagnies any South Vietnamese food. Canh chua is basically a milder version of the fiery Thai soup, tom yam which is more often prepared not with fish but with shrimps;it is usually eaten as a meal for itself with some fresh French bread (baguette); often, the pot is placed in the center of the table and each diner dips the bread into the soup.

Source :

European Masters Degree in Food Studies - an Educational Journey

Master in Food Safety Law is an initiative of Wageningen University, The Netherlands