What to know about Houttuynia cordata (fishfoil) before using it medicinally

Houttuynia cordata, commonly known as fishfoil, is a versatile herb that has been prized for its medicinal properties for centuries, with studies suggesting that it may possess anti-inflammatory, antioxidant, and antiviral effects that can help to improve cardiovascular health and reduce the risk of chronic diseases.

This hardy perennial herb is widely cultivated in warm and temperate climates for its attractive foliage and vibrant flowers, and is often used as a groundcover or in ornamental arrangements. Botanically, Houttuynia cordata belongs to the Saururaceae family and is characterized by its distinctive cordate-shaped leaves and showy, white flowers that resemble those of a forget-me-not.

With a long history of use in traditional Chinese medicine, Houttuynia cordata has been referenced in ancient texts such as the Shen Nong Ben Cao Jing, which dates back to the 2nd century AD.

This article explains the medicinal, horticultural, botanical, and historical aspects of Houttuynia cordata.

What are the medicinal properties of Houttuynia cordata?

Houttuynia cordata helps with treating fever, rheumatism, and gastrointestinal disorders. Its medicinal properties include antibacterial, anti-inflammatory, and antioxidant effects. Studies have shown its efficacy in reducing pain, swelling, and improving digestive health. It is also used to treat colds, coughs, and bronchitis.

The active constituents of Houttuynia cordata that contribute to its medicinal properties are alkaloids, flavonoids, and terpenoids. These compounds have been isolated and studied for their bioactive properties, including antimicrobial, anti-inflammatory, and antiviral effects. The specific chemical composition of the plant varies depending on the region and growing conditions.

The parts of the Houttuynia cordata plant most commonly used for medicinal purposes are the leaves, stems, and roots. The leaves contain the highest concentration of bioactive compounds, making them the primary focus of medicinal research. The stems and roots are also used, often in combination with the leaves, to enhance therapeutic effects.

When used improperly, Houttuynia cordata can cause adverse effects such as gastrointestinal upset, allergic reactions, and interaction with other medications. In some cases, excessive consumption of the plant can lead to toxicity, particularly in individuals with pre-existing kidney or liver conditions. It is essential to consult a healthcare professional before using the plant medicinally.

To ensure safe use of Houttuynia cordata, individuals should consult a healthcare professional, particularly if taking other medications or with pre-existing conditions. The recommended dosage and preparation method should be followed strictly to avoid adverse effects. Pregnant or breastfeeding women should exercise caution and consult their healthcare provider before using the plant medicinally.

What are the horticulural aspects of Houttuynia cordata?

Houttuynia cordata grow in moist, shaded areas with partial to full sun, preferring temperatures between 15-30°C (59-86°F). It thrives in acidic to neutral soil pH (5.5-7.0) with adequate moisture and moderate fertilization. Soil depth and drainage also influence growth.

Planting tips include choosing a location with consistent moisture and minimal root disturbance. Transplant seedlings after 1-2 weeks, 10-15cm apart, in spring or autumn. Water thoroughly and apply a thin layer of mulch to retain moisture and suppress weeds. Avoid over-fertilizing, as this may damage the plant.

Harvesting tips for Houttuynia cordata involve carefully cutting stems just above a node to encourage new growth. Leaves and stems are harvested in the morning when the plant is turgid. Harvest individual stems or cut entire plants, leaving a few inches to allow for regrowth. Timing depends on intended use, whether for cooking, medicinal, or ornamental purposes.

Common pests affecting Houttuynia cordata include aphids, spider mites, and snails. These can be managed using neem oil, insecticidal soap, and hand-picking. Fungal diseases such as powdery mildew and leaf spot can be controlled by improving air circulation, adjusting watering, and using fungicides. Regular monitoring helps prevent pest and disease infestations.

What are the botanical aspects of Houttuynia cordata?

Houttuynia cordata is a perennial herb belonging to the Saururaceae family. Its botanical characteristics include heart-shaped to oval leaves with serrated edges, measuring 5-15 cm long and 3-7 cm wide, with a short petiole. The leaf margins are often crinkled or wavy.

Taxonomically, Houttuynia cordata is classified as Saururaceae, a family of flowering plants, and is further grouped under the genus Houttuynia. Its scientific name is Houttuynia cordata Thunb. (Thunberg, 1794), and it is also known by other synonyms such as Saururus cordatus and Houttuynia cordata var. cordata.

There are several variants of Houttuynia cordata, including cultivars and hybrids, which differ in leaf shape and size, growth habit, and flowering behavior. Some popular cultivars include 'Chameleon', 'Pleniflora', and 'Golden Variegated'.

The geographical distribution of Houttuynia cordata is wide, with native habitats in East Asia, specifically in China, Japan, Korea, and parts of Southeast Asia. It has been naturalized in other regions, including Europe, North America, and Australia, due to human activity.

The life cycle of Houttuynia cordata typically begins with germination of seeds in spring, followed by vegetative growth and flowering in late spring to early summer. The plant reproduces via seeds and rhizomes, with flowering occurring on short, lateral stems.

What are the historical aspects of Houttuynia cordata?

Houttuynia cordata is a plant that has been used in traditional medicine for centuries. In ancient China, it was used to treat various health conditions, including fever, rheumatism, and respiratory problems. Its roots and leaves were used in teas, soups, and poultices.

In mythological references, Houttuynia cordata was associated with the god of war, Guan Gong, who used it to heal his wounded soldiers. In some Chinese cultures, the plant is believed to ward off evil spirits and bring good fortune. In Japan, it is associated with the concept of "yin-yang" balance.

In symbolic meanings, Houttuynia cordata represents harmony, balance, and stability. Its shape and structure are said to symbolize the unity of opposites. In China, it is considered a symbol of good luck, prosperity, and longevity.

Historical texts on Houttuynia cordata date back to the Tang Dynasty (618-907 CE) in China. The Bencao Gangmu, a comprehensive pharmacopeia, mentions the plant's medicinal properties and uses. In Japan, the Kusazoshi, a medical text from the Edo period (1603-1868 CE), also describes its therapeutic applications.

Historical artifacts related to Houttuynia cordata include ancient Chinese medical instruments, such as mortars and pestles, used to prepare medicinal teas and poultices. In Japan, ceramic vessels and pottery shards have been found with depictions of the plant, indicating its significance in traditional Japanese medicine.