Acorus terrestris Spreng., Acorus asiaticus Nakai.
|Malaysia||Jerangau, deringu, jerangoh (Peninsular).|
|English||Sweet flag, sweet root, calamus.|
|Indonesia||Daringo (Sundanese), dringo (Javanese), jerango (Sumatra).|
|Papua New Guinea||Lepe (Angi, Enga), eseue (Mendi, Southern Highlands), wamala (Aroma, Central Province).|
|Philippines||Lubigan (Tagalog, Bisaya), acoro (Spanish), daraw (Iloko).|
|Laos||Hang khao nam.|
|Thailand||Kha chiang chee (northern), wan nam (central), haang khaao phaa (Chiang Mai).|
|Vietnam||Th[ur]y x [uw] [ow]ng b[oof], x[uw][ow]ng b[oof], b[oof] b[oof] n[ees]p.|
|French||Calamus, acore odorant, acore vrai.|
A. calamus is probably native to China and India. Its use as a medicinal plant dates back to Egypt, Greek and Roman times. A. calamus was distributed from its native range by rhizomes through trade and commerce, and arrived in Europe in the 16th Century. In the Malesian region, it is considered as naturalized and not truly wild. It is found in many parts of Indonesia, Malaysia, and Papua New Guinea and locally in the Philippines (Bontoc and Benguet Provinces), and outside Malesia in Indo-China and Thailand. It is also cultivated here and there.
This perennial hairless herb can reach up to 150 cm tall. It has creeping rhizome. It is extensively branched, up to 3 cm in diametre. The herb is pale yellow to pinkish-brown on the outside and whitish but sometimes slightly pinkish on the inside. The upper surface is marked with large V-shaped leaf-scars and longitudinally furrowed. The surface beneath has circular pitted scars of rootlets arranged in irregular lines.
The aromatic leaves are erect, linear-ensiform with obliquely acuminate apex, often characteristically corrugated at one side in the upper part, with distinct midrib and numerous thin parallel veins. It is glossy green but often reddish towards base.
The 3-merous bisexual flowers are densely arranged on the spike. The 2-3 mm long narrowly oblong tepals are free, 6 in 2 whorls. The 3 mm long stamens are 6 and free, with strap shaped filaments and orbicular-elliptical anthers dehiscent by a longitudinal slit. The ovary is superior, subquadrangular, 2-3-celled with sessile stigma. It is sub-conical.
The fruit is a 2-3-celled berry, turbinate and prismatic with pyramidal top, few-seeded and reddish.
Seeds are ellipsoid.
A. calamus is a component of semi-aquatic habitats, usually in eutrophic locations. It can be a vigorous invader of new sites. In Malesia, it is found along ditches, pools, fish-ponds and marshes, and is sometimes cultivated. In Java, it is found up to 2100 m altitude. A. calamus can be planted on clayey loams and light alluvial soils.
Plant Resources of South-East Asia No 12(2). 1998, Unesco.