[Java Water Dropwort, Water Celery, Vietnamese Celery; Minari (Korea); Rau Can, Can Nuoc (Viet); Seri (Japan); Komprek (Manipur, India); Oenanthe javanica]
Most Water Dropworts (Genus Oenanthe) are toxic to extremely toxic, but this one, native to East Asia, is edible. Its thin hollow stems are topped with celery-like leaves. This plant is sometimes called "Chinese celery" and "Japanese parsley", but those names properly belong to completely different plants (both found on our Parsley page). This plant is also grown in Italy as spring greens, and is an invasive in some parts of North America, but not an aggressive one.
Many recipes, calling this plant "Korean Watercress", and say Watercress is a suitable substitute, but it rally isn't. The flavor and texture are very different. This plant tastes more like a mix of carrot tops and celery, with a hint of resin. The specimen bundle, purchased at a local Korean market in Los Angeles, was about 15 inches long.
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Minari is particularly popular in Korea, where it is sold in long stemmed bundles. While all parts of the plant are edible, many Korean recipes call just for the tender stems, with leaves removed. In Japan, the leaves are often used in soups and salads, and the roots are also cooked and eaten.
Buying & Storing: This herb can be found fresh in some well stocked Korean markets, in the vegetable section, but quality can vary considerably from day to day. I have also recently found it (3 2017) in a large Asian market in San Gabriel at 2017 US $2.99 / pound. The plant wilts fairly quickly, so should be kept loosely bagged in the fridge and used soon after purchase.
Subst: This is a difficult problem. Probably thin strips of celery are your best bet, particularly if cut from above the first joint, up where the leaves are.