Grass-leaved Sweet Rush, Japanese Sweet Flag, Dwarf Sweet Flag

Acorus gramineus

Physical Characteristics

Acorus gramineus is an evergreen Perennial growing to 0.3 m (1ft) by 0.2 m (0ft 8in). See above for USDA hardiness. It is hardy to UK zone 5 and is not frost tender. It is in leaf all year, in flower from June to July, and the seeds ripen from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist or wet soil and can grow in water.

Distribution

E. Asia - China, Japan, India.

Habitats

Ground Cover; Pond; Bog Garden;

Edible Uses

Edible Parts: Root Edible Uses: Condiment Root - raw or cooked[105, 177]. It should be peeled, finely chopped and soaked in several changes of water first[183]. A stronger and more pleasing taste than A. calamus[2, 183]. The root is also used as a ginger substitute[177]. Some caution is advised, see the notes above on toxicity.

Medicinal Uses

Anodyne Antibacterial Antifungal Antiperiodic Antirheumatic Antispasmodic Aromatic Cardiac Carminative Diaphoretic Diuretic Emmenagogue Epilepsy Expectorant Febrifuge Parasiticide Sedative Stimulant Stomachic Tonic Vermifuge The root is antifungal, antibacterial, antiperiodic, antirheumatic, antispasmodic, aromatic, cardiac, carminative, diaphoretic, emmenaggue, febrifuge, sedative, stimulant, stomachic, tonic and vermifuge[4, 7, 9, 21, 61, 147, 165, 176, 178, 218, 238, 240, 279]. It is also powdered and applied to bleeding gums[218, 238]. It is used internally in the treatment of digestive problems - particularly gastralgia and diarrhoea[283], cough, bronchial asthma, neurasthenia, depression, epilepsy etc[176, 238, 283]. Externally, it is used to treat body parasites, dermatosis and haemorrhoids[283]. The root can be harvested at any time of the year, except when the plant is in flower[238]. The root contains an essential oil consisting of asarone and asaryl aldehyde, plus a bitter glucoside acorin[176, 283]. Asarone increases the hypnotic effect of barbiturates and ethanol, lowers blood pressure and is antibacterial against Staphylococcus aureus, streptococci and mycobacterium[176]. The whole plant is anodyne, antiperiodic, antispasmodic, digestive, diaphoretic, diuretic, expectorant, sedative, stimulant, stomachic, sudorific, tonic, vermifuge[218].

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[7]. When using the plant medicinally, the isolated essential oil should not be used[165].