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Acorus
Also called Sweet-flag, Calamus, Sweet Flags
Acorus is a genus of marsh and wetland monocots, including sweetflag (A. calamus) and the North American A. americanus, grown for their sweet-scented, sword-like leaves. Keep the roots wet or submerged and give them sun to part shade.
Acorus is a genus of monocot flowering plants. This genus was once placed within the family Araceae (aroids), but more recent classifications place it in its own family Acoraceae and order Acorales, of which it is the sole genus of the oldest surviving line of monocots. Some older studies indicated that it was placed in a lineage (the order Alismatales), that also includes aroids (Araceae), Tofieldiaceae, and several families of aquatic monocots (e.g., Alismataceae, Posidoniaceae). However, modern phylogenetic studies demonstrate that Acorus is sister to all other monocots. Common names include calamus and sweet flag.
The genus is native to North America and northern and eastern Asia, and naturalised in southern Asia and Europe from ancient cultivation.
Products derived from Acorus calamus were banned in 1968 as food additives by the United States Food and Drug Administration. The primary chemical responsible for the plant's toxic and carcinogenic effects is β-asarone. Confusion exists whether all strains of A. calamus contain this substance.
Four varieties of A. calamus strains exist in nature: diploid, triploid, tetraploid and hexaploid. Diploids do not produce the carcinogenic β-asarone. Diploids are known to grow naturally in Eastern Asia (Mongolia and C Siberia) and North America. The triploid cytotype probably originated in the Himalayan region, as a hybrid between the diploid and tetraploid cytotypes. The North American Calamus is known as Acorus calamus var. americanus or more recently as simply Acorus americanus. Like the diploid strains of A. calamus in parts of the Himalayas, Mongolia, and C Siberia, the North American diploid strain does not contain the carcinogenic β-asarone. Research has consistently demonstrated that "β-asarone was not detectable in the North American spontaneous diploid Acorus [calamus var.
These plants are found in wetlands, particularly marshes, where they spread by means of thick rhizomes. Like many other marsh plants, they depend upon aerenchyma to transport oxygen to the rooting zone. They frequently occur on shorelines and floodplains where water levels fluctuate seasonally.
The parallel-veined leaves of some species contain ethereal oils that give a sweet scent when dried. Fine-cut leaves used to be strewn across the floor in the Middle Ages, both for the scent, and for presumed efficacy against pests.
Text excerpted from the Wikipedia article Acorus by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
