Botanical Name calamus L. (Acorus calamus L.)
Synonyms -
Family Acoraceae
Local Name Bojho
English Name Sweet Flag

Plant Description

Sweet Flag is a perennial, semi-aquatic, erect, aromatic, herb reaching up to 70 em in height. The plant have thick creeping root. Leaves are distichous, with parallel nerves. Spathe are leaf like with small yellow green bisexual flowers. It is distributed throughout Nepal within the altitudinal range of 200-2300m in wet, marshy places. It grows on the margins of lakes and streams with long branched rhizomes immersed in mud.


Calamus oil is extracted from the steam distillation of the dried rhizomes of Acarus calamus.


The oil is used as anticonvulsant, antiseptic, bactericidal, carminative, diaphoretic, expectorant, insecticide, stimulant, stomachic, tonic, vermifuge, hypotensive, spasmolytic etc. Calamus causes increased dilation of spleenic vessels, an important factor in regulating blood pressure.

Since the oil is reported to have carcinogenic properties,it is not recommended for internal use.

The oil is used in perfumery and to scent hair powders. Oil is added to mouth washes and used to flavour the alcoholic beverages.

Organoleptic Properties

Appearance: Slightly Viscous Fluid
Colour: Yellow or yellowish brown
Aroma: Warm woody-spicy

Active Constituents

Major constituents of Calamus oil are a- asarone, a-terpinolene, 13-asarone, acorenone, clamene, calamol, calamenene,iso-calamendiol,methyl iso-eugenol, trans- β - ocimene etc.

Physico-Chemical Properties

Specific gravity 1.0695 to 1.0795 at 25°C?>
Optical rotation 0° to (+)4° at 25°C?>
Refractive index 1.495 to 1.5589 at 25°C?>
Acid number 0.6 to 2.5
Ester number 2 to 12
Ester number 8.5 to 12 (after acetylation) (after acetylation)
Solubility Soluble in 0.4 to 1.5 volumes of 80% alcohol, insoluble in water