Rau Om, Rice Paddy Herb (Limnophila aromatica)
Rice paddy herb (Limnophila aromatica, rau om, ngò om, phak khayang, seui fa and shui fu rong) is a great example of the botanical-dietary paradox of agricultural ecosystems in Southeast Asia. Countries in the Asia-Pacific Region produce and consume over 90 percent of the world’s rice, which has a significant impact on the biodiversity of plants and diets in the area. When edible aquatic plants like rice paddy herb creep up from normally homogenous rice paddy fields, they must be weeded out. But nothing goes to waste, and farmers may seek out the plants to use them in cooking.
Limnophila aromatica is a standout plant, with spirals of narrow leaves with hues of red, green, and purple. The color and growth can be manipulated by changing the intensity of light and carbon dioxide levels. As an aquatic plant, rice paddy herb will thrive in hot and humid environments. It will thrive in hard water, but can grow either submersed or emersed. Harvest rice paddy herb to use it raw, added as an accompaniment to Thai plates like pho or curry. It is best used as a garnish, with a flavor similar to lemon and cumin.