Common Name: Tsi

General Information

Houttuynia cordata is an erect to ascending, herbaceous perennial plant growing from a rhizomatous rootstock. The stems are creeping near their base, often rooting at leaf nodes, and the plant forming a cluster or mat of growth from 5 - 60cm tall[].
The plant is harvested from the wild for local use as a food and a medicine. It is cultivated for medicinal and food use in eastern Asia and is also often grown as an ornamental, where it can be used to form a ground cover.

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - central and southern China, Japan, Korea, northern India, Napal, Bangladesh, Myanmar, Thailand, Vietnam, Laos

Habitat

Ravines, streamsides, forests, wet meadows, slopes, thicket and field margins, trailsides, roadsides, ditch banks; at elevations from near sea level to 2,500 metres[]. Often found as a weed in wet fields[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.60 m
Growth Rate	Fast
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Houttuynia cordata is a moderately hardy plant, able to withstand temperatures down to at least -15°c when it is dormant. The top growth is more tender, however, and young growth in spring can be killed back by quite light frosts, though the plant will usually resprout vigorously from the roots[, ]. Even the roots, though, can be killed in severe winters[].
Requires a moist to wet soil or shallow water, partial shade and a sheltered position[, , , ]. Whilst it grows best in a bog garden, it will succeed in moist garden borders[] and has also grown fairly well in a dry soil in Cornwall[]. It succeeds in full shade[].
The plant is cultivated as a salad crop and medicinal plant in Vietnam and in China[, ].
A very ornamental plant, there are some named varieties[]. 'Chameleon' has very attractively variegated leaves with the same flavour as the species[]. The bruised leaves emit a strong citrus smell rather like orange peel[].
Plants have a widely spreading root system and can be very invasive, though they are easier to control in drier soils[]. The plant creeps harmlessly between ferns[].
Plants seem to be immune to the predations of rabbits[]. Plants growing in an area with a high rabbit population were not eaten by them although other plants growing nearby were attacked[].

Edible Uses

Tender young shoots and leaves - raw or cooked as a pot-herb[, , , , ]. The leaves and young shoots are harvested in the spring when about 8cm long[]. Strongly aromatic according to one report[] whilst others say that it is rather smelly and somewhat like rotten fish[, ]. Our experience is that the leaves have a delicious orange-like smell and make a marvellous flavouring in salads[].
One report says that there are two distinct chemotypes of this species. Plants from Japan have an orange scent, whilst those from China have a smell resembling coriander leaves (Coriandrum sativum)[].
Some people seem to really like this leaf, others are indifferent to it or strongly dislike it[]. It also varies quite considerably according to the time of year. In the spring and summer it has a very acceptable flavour, but by autumn a distinct bitterness has crept in[].

Root - cooked[, ]. Same comments on the smell as for the leaves[].

Fruit[]. No further details[], but the fruit is a capsule that contains many small seeds[].

Medicinal

The whole plant is antibacterial, antiinflammatory, antimicrobial, antiphlogistic, antiviral, depurative, diuretic, emmenagogue, febrifuge, hypoglycaemic, laxative and ophthalmic[, , , , , , , , ]. A decoction is used internally in the treatment of many ailments including irregular menstruation, measles, cancer, coughs, dysentery, enteritis and fever[], 283. Its use is said to strengthen the immune system[].
Externally, it is used in the treatment of snake bites and skin disorders[]. The crushed fresh leaves arc applied externally in a poultice in the treatment of contusions and ophthalmia[].
The leaves and stems are harvested during the growing season and used fresh in decoctions[].

The leaf juice is antidote and astringent[].

A root extract is diuretic[, ]. The root is also said to be used in medicinal preparations for certain diseases of women[, ].

The rhizomes yield a sterol, resembling sitosterol, which stimulates the secretion of antibiotic substances from a gram-positive spore-forming bacillus[].
An active substance, effective in the treatment of stomach ulcers, has been extracted from the plant[].

Agroforestry Uses:

A good ground cover plant[]. Plants do not form a weed-suppressing cover[]. A spreading plant, it should be spaced about 45cm apart each way[].

Other Uses

None known

Propagation

Seed - sow spring in a greenhouse. Prick out the seedlings into individual pots as soon as they are large enough to handle and plant them out in the summer.
Division in spring[, ]. Very quick and easy, it can be done successfully at almost any time in the growing season[]. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.