Grass-leaved Sweet Rush, Japanese Sweet Flag, Dwarf Sweet Flag
Acorus gramineus
Family: Araceae
What it is like
Bloom Color: Green. Main Bloom Time: Early summer, Late summer, Mid summer. Form: Rounded.
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.
Height (m): 0.3
Where it is found
Wet places by streams and around ponds in C. and S. Japan.
E. Asia - China, Japan, India.
Conservation Status:
Countries/locations it is found in
Asia, Australia, Cambodia, Canada, China, India, Indochina, Japan, Korea, Laos, Malaysia, Myanmar, North America, Northeastern India, Philippines, Russia, SE Asia, Siberia, Taiwan, Thailand, Tibet, Vietnam. Native to: Bangladesh, Cambodia, China North-Central, China South-Central, China Southeast, East Himalaya, Hainan, Inner Mongolia, Japan, Korea, Laos, Myanmar, Philippines, Primorye, Qinghai, Taiwan, Thailand, Tibet, Vietnam, Xinjiang.
How it is used
Food
Rating: 3
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 A. calamus. The root is also used as a ginger substitute. Some caution is advised, see the notes above on toxicity.
Root: includes bulbs, corms, tubers, rhizomes etc.
Condiment: the various plants that are used as flavourings, either as herbs, spices or condiments.
Medicine
Rating: 3
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 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. The whole plant is anodyne, antiperiodic, antispasmodic, digestive, diaphoretic, diuretic, expectorant, sedative, stimulant, stomachic, sudorific, tonic, vermifuge.
Anodyne: Relieves pain, it is milder than an analgesic.
Antibacterial: Kills bacteria.
Antifungal: An agent that inhibits or destroys fungi. Used in the treatment of various fungal problems such as candida.
Antiperiodic: Counteracts recurring illnesses such as malaria.
Antirheumatic: Treats rheumatism.
Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.
Aromatic: Having an agreeable odour and stimulant qualities.
Cardiac: Used in the treatment of heart problems.
Carminative: Reduces flatulence and expels gas from the intestines.
Diaphoretic: Induces perspiration.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Emmenagogue: Promotes or increases the menstrual flow. In early stages of pregnancy it can induce an abortion.
Epilepsy: Used in the treatment of Epilepsy - a disorder in which nerve cell activity in the brain is disturbed, causing seizures.
Expectorant: Clears phlegm from the chest by inducing coughing.
Febrifuge: Reduces fevers.
Parasiticide: Treats external parasites such as ringworm This should perhaps be joined with Parasiticide in
Sedative: Gently calms, reducing nervousness, distress and irritation.
Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.
Stomachic: Aids and improves the action of the stomach.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Vermifuge: Expels and kills internal parasites.
Other
Rating: 0
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. A useful ground cover plant, forming a spreading clump.
Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.
Insecticide: Kills insects.
Parasiticide: Kills external body parasites such as hair lice.
Repellent: Plants that are said to deter but not necessarily kill various mammals, birds, insects etc.
Ground cover: Ground Cover
Scented Plants: Plants noted for their scent
How it is grown
Landscape Uses:Container, Foundation, Ground cover, Massing, Rock garden, Seashore. Grows well in shallow water margins of ponds etc, though it can also succeeds in drier habitats. Requires a sunny position. A very ornamental plant, there are some named varieties. The cultivar 'Pusillus' can be grown as a submerged aquatic plant. Special Features:Attractive foliage, Fragrant foliage, Not North American native, Naturalizing, Wetlands plant, Inconspicuous flowers or blooms.
Propagating it: 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.
Best place to grow: Ground Cover; Pond; Bog Garden;
Habit: Perennial
Hardiness: 6-10
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist, wet, water
Things to keep in mind
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.