Houttuynia cordata, commonly known as chameleon plant, fish mint, or dokudami, is a shade-loving herbaceous perennial plant in the family Saururaceae. It is native to Southeast Asia, spanning from the Himalayas to Japan and Indonesia, where it typically thrives in damp, marshy, or shaded forest environments. The genus name Houttuynia honors the Dutch botanist Maarten Houttuyn, while the species epithet cordata is Latin for "heart-shaped," referring to the distinctive morphology of its leaves. Historically, this plant has played a vital role in both Asian culinary traditions and East Asian medical systems, where it is considered a premier "cleansing" herb for internal detoxification and skin health.

The plant features a creeping rhizomatous root system that allows it to spread rapidly across damp soil. Its stems are often reddish, bearing characteristic alternate, heart-shaped leaves that can vary in color from deep green to striking shades of yellow, cream, and red—a trait that has made it a popular ornamental groundcover in Western gardens. In late spring and summer, it produces small, unassuming yellowish-green inflorescences surrounded by four conspicuous white petal-like bracts, which give the appearance of a single, showy white flower. Houttuynia cordata is exceptionally hardy and can become invasive in garden settings due to its aggressive vegetative spread, but it is highly valued in permaculture for its ability to stabilize wet or problematic soil.

As a food source, Houttuynia cordata is a polarizing ingredient, defined by its intense, pungent, and distinctively "fishy" aroma and flavor profile. In Vietnamese cuisine, it is a staple fresh herb (diếp cá), frequently served raw in salads, tucked into spring rolls, or added as a garnish to grilled meat dishes and soups to provide a sharp, clean contrast to fatty flavors. In southwestern Chinese provinces like Yunnan and Guizhou, the rhizomes are heavily utilized as a crunchy, earthy, and spicy-tasting vegetable, often stir-fried with chilies or prepared as a cold salad with vinegar, soy sauce, and garlic. The "fishy" quality is due to the presence of specific volatile aldehydes, which dissipate slightly when cooked but remain strong and refreshing in their raw state.

Nutritionally, Houttuynia cordata is prized not for its caloric content, but for its potent phytochemical density. It is rich in Vitamin C, potassium, and various flavonoids. Its defining biochemical feature is the presence of specialized volatile oils, including decanoyl acetaldehyde (which contributes the fishy scent and possesses strong antimicrobial properties) and methyl-n-nonyl ketone. In Traditional Chinese Medicine (TCM) and Japanese Kampo, it is known as yuxingcao or dokudami, and it is widely consumed as a herbal tea or decoction to address respiratory infections, urinary tract inflammation, and skin conditions. Modern pharmacological research confirms its therapeutic potential, highlighting its antiviral, anti-inflammatory, and diuretic effects, with scientists particularly interested in its ability to inhibit viral replication and modulate the immune system.