There has been considereable confusion in the past over the correct naming of this species, with many authorities using the name Pueraria lobata (Willd.) Ohwi as the correct name and Pueraria montana (Lour.) Merr., as a form of that species. Opinion is now generally reversed and Pueraria lobata is now commonly seen as a form of Pueraria montana, as Pueraria montana lobata (Willd.) Sanjappa & Pradeep[].

Common Name: Mealy Kudzu

General Information

Pueraria montana is a vigorous, perennial climbing plant producing annual, twining stems from a large, tuberous rootstock that can be up to 2 metres long and 45cm in diameter. The stems can reach 15 - 30 metres or more in length and are up to 10cm in diameter, becoming woody at the base. They scramble over the ground, producing new roots where stem nodes touch the soil and often forming dense carpets over the ground. They also climb high into any trees or shrubs around them and can completely smother forest trees[, , , ].
A very useful plant, supplying food, medicines and fibre, as well as being grown in soil conservation projects. It was at one time very widely grown for its edible root and useful fibre, especially in east and southeast Asia and the Pacific Islands[]. It is reputed to be the oldest fibre crop in China and Japan, being mentioned in documents over 2,000 years ago[]. Nowadays it has mostly lost its former importance, cultivation has been abandoned (e.g. In Pacific Islands.) or reduced to a relic state[]. Cultivation, however, is still practised considerably in the highlands of New Guinea, New Caledonia, northern Philippines and in Japan.
When grown in warm climates, the root can be invasive and plants have become weeds[, ]. Introduced into the southern N. American states in 1876 as a soil stabilizer, the var lobata has spread very widely (it can grow up to 30cm in a day), and has swamped out native vegetation, including large trees. It is considered to be one of the most obnoxious weeds in that region, though it has not become weedy elsewhere[, ].

Known Hazards

Although no specific mention has been found for this species, the leaves of the closely related Pueraria hirsuta (which might be no more than a synonym for this species) have barbed hairs and these can cause severe irritation[].

Botanical References

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Range

E. Asia - China, Japan, Korea, Myanmar, Thailand, Laos, Vietnam, Malaysia, Indonesia, Philippines. New Guinea,th the Solomon Islands and Vanuatu.

Habitat

Thickets and thin woods all over Japan[]. Thickets, forests, on dry slopes or in moist places, in sandy or loamy soils, valleys, roadsides, open pastures, hedges, river sides, swamps; at elevations up to 1,500 metres[]..

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial Climber
Height	10.00 m
Pollinators	Bees, Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Kudzu vine can be grown in a wide range of climates from milder areas in the temperate zone to the subtropics and higher elevations in the tropics. It grows best in areas where annual daytime temperatures are within the range 18 - 28°c, but can tolerate 9 - 32°c[]. When dormant, the plant can survive temperatures down to about -6°c, but young growth can be severely damaged at -1°c[]. Plants are hardy to about -15°c, they can resprout from the base if they are cut down by frosts[]. It prefers a mean annual rainfall in the range 1,200 - 1,400mm, but tolerates 950 - 2,200mm[].
Succeeds in most well-drained soils in a sunny position[], though it does not make good growth on very light poor sand or on poorly drained heavy clay[]. Grows best on well-drained loam soil of good fertility[]. Plants cannot stand waterlogging on any soil[]. Prefers a pH in the range 5.5 - 6.5, tolerating 5 - 7.1[, ]. A deep-rooted pant, once established it is very drought resistant[, ].
The tubers can be harvested about 1 year after planting, if grown from cuttings. If left longer in the soil they can become very large, with weights of up to 180 kilos[].
Pueraria montana has three varieties, all of which can be used more or less interchangeably:-
Pueraria montana montana. This form has the smallest flowers.
Pueraria montana lobata (Willd.) Maesen & S.M.Almeida ex Sanjappa & Predeep. This is the form most commonly cultivated outside its native range. It has become an extremely invasive weed in southeastern USA, though it has not yet become invasive elsewhere[]. It is also the form most commonly mentioned for its medicinal and other uses.
Pueraria montana thomsonii (Benth.) M.R.Almeida. This form has the largest flowers.
The flowers have a sweet vanilla scent[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Root - cooked[, ]. Rich in starch[]. The root can be up to 1.8 metres long[] and has been known to weigh 35 kilos or more[]. One report is of a mature tuber weighing 180 kilos[]. The root contains about 10% of a fine quality starch - this can be extracted and used as a crispy coating in deep fried foods, or as a thickening agent in soups etc[, , ]. It can also be made into noodles, or like agar or gelatine is used as a gelling agent for salads[]. The roots are a staple food in Japan, the peeled root contains about 2.1% protein, 0.1% fat, 27.1% carbohydrate, 1.4% ash[]. The starch of the roots contains (per 100 g) 340 calories, 16.5 percent moisture, 0.2 g protein, 0.1 g fat, 83.1 g total carbohydrate, 0.1 g ash, 35 mg Ca, 18 mg P, 2.0 mg Fe, and 2 mg Na[]. A nutritional analysis for the whole root is available.

Flowers - cooked or made into pickles[]. Eaten as a vegetable[].

Stems and young leaves - raw or cooked[]. Eaten as a vegetable[]. A very nutritious food, the fresh young shoots taste like a cross between a bean and a pea[]. The cooked leaves contain (per 100 g) 36 calories, 89.0 percent moisture, 0.4 g protein, 0.1 g fat, 9.7 g total carbohydrate. 7.7 g fibre, 0.8 fat, 34 mg Ca, 20 mg P, 4.9 mg Fe, 0.03 mg thiamine, 0.91 mg riboflavin, 0.8 mg niacin[].

Medicinal

The kudzu vine, known as Ge Gen in China, is commonly used in oriental herbalism, and is considered to be one of the 50 fundamental herbs in Chinese herbalism[]. All parts of the plant are used medicinally, particularly the starch-rich root. Kudzu starch is used to restore the health, acting by alkalinizing the bloodstream and fighting intestinal and digestive disorders. The starch is then mainly taken in soups or teas. As a diet food it is soothing, nutritious and easy to digest[].

The flowers and the roots are antidote, antiemetic, antipyretic, antispasmodic, demulcent, diaphoretic, digestive, febrifuge, hypoglycaemic and hypotensive[, , , , ]. A decoction of the flowers and tubers is used to treat alcoholism, fever, colds, diarrhoea, dysentery, acute intestinal obstruction etc[, , , ]. It is useful in the treatment of angina pectoris and migraine[]. The root is frequently used as a remedy for measles, often in combination with Cimicifuga foetida[].

The flower buds are diaphoretic and febrifuge[].

Research has shown that compounds called 'daidzin' and 'daidzein', which are contained in the roots and the flowers, are a safe and effective method for treating alcohol abuse[]. They work by suppressing the appetite for alcohol, whereas existing treatments interfere with the way the alcohol is metabolised and can cause a build-up of toxins[]. The plant is often used in combination with Chrysanthemum x morifolium in treating alcohol abuse[].
The root contains puerarin. This increases the blood flow to the coronary artery and protects against acute myocardial ischaemia caused by the injection of pituitrin[].
The root can be harvested from the autumn to the spring and is used fresh or dried[].

The flowers are harvested just before they are fully open and are dried for later use[].

The stems are galactagogue and are also applied as a poultice to incipient boils, swellings, sore mouths etc[, ].

The seed is used in the treatment of hangover and dysentery[, ].

The leaves are styptic[].

Agroforestry Uses:

The plant can be used as a ground cover in a sunny position[]. It can also be used to make a quick, temporary screen[].
Plants are very fast-growing and have an extensive root system which can be 1.8 metres deep. They are used for erosion control and for rebuilding depleted soils[, ]. A member of the Fabaceae, the plant also adds nitrogen to the soil through the actions of root bacteria.

Other Uses

A tough, strong fibre from the stems is used to make ropes, cables, coarse cordage and textiles[, , , , ]. The fibre is 2 - 3mm long and can be used to make paper. Straight first year stems, 2 - 2.7 metres long, are harvested in mid summer, the leaves are removed and the stems steamed until the fibres can be stripped. The fibres are then cooked for 2 hours with lye, tough vines might require 4 hours cooking, and the fibre put in a ball mill for 3 hours. The resulting paper is greenish/cream in colour[].

Propagation

Pre-soak the seed for 12 hours in warm water and sow in a warm greenhouse in early spring. Germination should take place within 2 weeks. Prick out the seedlings into individual pots when they are large enough to handle and plant them out after the last expected frosts[]. Cover the young plants with a frame or cloche until they are growing away well.