Common Name: Grass-leaved Sweet Rush

General Information

Acorus gramineus is a stemless herbaceous perennial plant that can be evergreen in tropical areas. It produces a dense, slowly-spreading clump of sword-shaped leaves up to 50cm tall from an extensively-branched, creeping, slender rhizomer[, ].
The plant is harvested from the wild for local use as a food, medicine and source of an essential oil. It is a very ornamental plant, making a good ground cover - there are some named varieties[, ].

Known Hazards

Although no records of toxicity have been seen, this species belongs to a family where most of the species are poisonous, at least in the fresh state. The following notes are from the related A. calamus - the fresh root can be poisonous[]. When using the plant medicinally, the isolated essential oil should not be used[].

Botanical References

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Range

E. Asia - China, Japan, Korea, India, Bangladesh, Myanmar, Thailand, Cambodia, Laos, Vietnam, Philippines.

Habitat

Wet places by streams and around ponds in central and southern Japan[]. Dense forests, moist rocky stream banks, meadows; at elevations below 2,600 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Perennial
Height	0.30 m
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Acorus gramineus has a very wide range from the temperate zone of central China, southwardesthrough the subtropics and tropics of northeastern India, Myanmar, Indo-China and the Philippines.
Grows well in shallow water margins of ponds etc[, ], though it can also succeeds in drier habitats[]. Requires a sunny position[].
The cultivar 'Pusillus' can be grown as a submerged aquatic plant[].

Edible Uses

Root - raw or cooked[, ]. It should be peeled, finely chopped and soaked in several changes of water first[]. A stronger and more pleasing taste than Acorus calamus[, ]. The root is also used as a ginger substitute[].
Some caution is advised, see the notes above on toxicity.

Medicinal

The root is antifungal, antibacterial, antiperiodic, antirheumatic, antispasmodic, aromatic, cardiac, carminative, diaphoretic, emmenaggue, febrifuge, sedative, stimulant, stomachic, tonic and vermifuge[, , , , , , , , , , , , ]. It is also powdered and applied to bleeding gums[, ]. It is used internally in the treatment of digestive problems - particularly gastralgia and diarrhoea[], cough, bronchial asthma, neurasthenia, depression, epilepsy etc[, , ].
Externally, it is used to treat body parasites, dermatosis and haemorrhoids[]. The root can be harvested at any time of the year, except when the plant is in flower[].

The whole plant is anodyne, antiperiodic, antispasmodic, digestive, diaphoretic, diuretic, expectorant, sedative, stimulant, stomachic, sudorific, tonic, vermifuge[].

The root contains an essential oil consisting of asarone and asaryl aldehyde, plus a bitter glucoside acorin[, ]. Asarone increases the hypnotic effect of barbiturates and ethanol, lowers blood pressure and is antibacterial against Staphylococcus aureus, streptococci and mycobacterium[].

Agroforestry Uses:

A useful ground cover plant, forming a dense, slowly-spreading clump[]. Plants need to be grown fairly densely, within 20cm of each other, for a good cover to be formed within a couple of years[].

Other Uses

The dried root repels insects[]. It is probably also insecticidal[, ] and is used in Vietnam to kill lice, bugs and fleas[].

An essential oil is obtained from the plant[].

Propagation

Seed - best sown in a cold frame as soon as it is ripe. Stand the pot in about 3cm of water. Pot up young seedlings as soon as they are large enough to handle, keep them wet by standing the pots in shallow water and overwinter for the first year in a greenhouse or cold frame.
Division in spring just before growth starts[]. Very easy, the plants can be divided at any time in the growing season and can be planted direct into their permanent positions[].