Common Name: Alang-alang

General Information

Imperata cylindrica is a perennial grass growing around 120cm tall and forming extensive clumps by means of its aggressively spreading rhizomes[].
Considered to be a noxious weed in many areas of the tropics, it is sometimes harvested from the wild for its wide range of edible, medicinal and other uses. It is sometimes used in soil stabilization schemes.
Although it has a wide range of useful attributes, alang-alang is also a widespread, weed of disturbed ground and cultivated areas - indeed, it is considered to be one of the 10 most noxious weeds in the world. It spreads vigorously by its rhizomes, which descend deep into the soil and are almost impossible to eradicate. The plant rapidly invades native areas, outcompeting the native vegetation, and may cover very large areas of ground, and flourishes particularly well in grasslands that are frequently burned[]. Plants grow away vigorously after a fire, often spreading freely to infest the burnt areas[, ].

Known Hazards

None known

Botanical References

, ,

Range

A widespread weed, found in warm temperate to tropical areas of the world.

Habitat

Open sandy habitats, usually by a river or the sea shore in Europe[]. Commonly found on impoverished soils in Australia[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.20 m
Pollinators	Wind
Cultivation Status	Cultivated, Wild

Cultivation Details

A plant of the tropics and subtropics, where it is found at elevations up to 2,000 metres. It grows best in areas where annual daytime temperatures are within the range 25 - 35°c, but can tolerate 20 - 40°c[]. It is moderately cold-hardy, tolerating short periods with temperatures falling as low as -15°c when it is dormant, and so can be grown outdoors in milder regions of the temperate zone. It prefers a mean annual rainfall in the range 500 - 3,500mm, but tolerates 250 - 6,250mm[].
Succeeds in ordinary garden soil in sun or partial shade[, ]. Prefers a pH in the range 4.5 - 6, tolerating 4 - 7.5[]. Established plants are drought tolerant[].
The var. Imperata cylindrica major is used medicinally in China[] and as a wild food in Australia[].
An extremely polymorphic species[].
This species is quite closely related to sugar cane, it has been interbred experimentally with that species in India[].

Edible Uses

Young inflorescence and young shoots - cooked[, ].

Root - fibrous but pleasant to chew, containing starch and sugar[, , ]. Fairly sweet, the taste is sweetest in the wet season in Australia and worst from plants growing in sand[].

The ash of the plant is used as a salt substitute[].

Medicinal

The flowers and the roots are antibacterial, diuretic, febrifuge, sialagogue, styptic and tonic[, , ].
The flowers are used in the treatment of haemorrhages, wounds etc[]. They are decocted and used to treat urinary tract infections, fevers, thirst etc[, ].

The root is astringent, antifebrile, antivinous, diuretic, emollient, haemostatic, restorative and tonic[, ]. It is used in the treatment of nose bleeds, haematuria, haematemesis, oedema and jaundice[]. The root has antibacterial action against Staphylococcus aureus, Bacillus dysenteriae etc[]. A decoction of the root is used as an anthelmintic and also to treat digestive disorders such as indigestion, diarrhoea and dysentery[]. It is often combined with the corn silks of Zea mays in order to enhance the diuretic action[].
The root bark is febrifuge, restorative and tonic[].
The root, or rhizome, can be harvested the whole year round. It can be washed and then well dried in the sun or in an oven for later use[].

Extracts of the plant have shown viricidal and anticancer activity[].

Agroforestry Uses:

Can be planted on sandy soils to prevent erosion[, ]. The plants form impenetrably dense clumps and when planted close together in drifts make an excellent ground cover[].

Other Uses

The leaves are woven to make mats, bags and raincoats[, , ].

The inflorescences are valued for stuffing pillows and cushions[].

The stems are used in thatching roofs[, , , ].

A fibre obtained from the leaves is used in making paper[, , ].

Propagation

Seed - surface sow in spring in a greenhouse. The seed germinates quickly, prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer.
Division in spring as the plant comes into growth. Division is very easy and can be carried out at almost any time in the year, though winter divisions are best potted up in the greenhouse and planted out in late spring[].