*Acorus calamus Linnaeus. Common name: European Calamus, Sweetflag. Phenology: May-Jun. Habitat: Marshes, wet meadows, other wet areas. Distribution: Native of Eurasia, now widespread in e. North America.
Origin/Endemic status: Eurasia
Taxonomy Comments: Following the taxonomy of Sokoloff et al. (2024), A. calamus consists of sterile triploids in Europe, w. Asia, and (presumably introduced) e. North America; diploid and tetraploid populations (in Asia) previously interpreted as part of A. calamus represent different species.
Other Comments: The aromatic rhizome and leaves have been used medicinally and candied as a confection.
Synonymy ⓘ: = AqW, Ar, Can, ETx1, FNA22, Il, K4, Mi, Mo1, NcTx, NE, NS, NY, Ok, Pa, POWO, Tx, Va, Spaulding et al (2019); < Acorus americanus (Raf.) Raf. — W; < Acorus calamus L. — C, F, G, GrPl, GW1, NeUS, RAB, S, S13, Tat. Basionym: Acorus calamus L. 1753
Links to other floras: = Acorus calamus - FNA22
Show parent genus | Show parent in key(s)
Wetland Indicator Status:
- Atlantic and Gulf Coastal Plain: OBL
- Eastern Mountains and Piedmont: OBL
- Great Plains: OBL
- Midwest: OBL
- Northcentral & Northeast: OBL
Heliophily ⓘ: 9
Hover over a shape, letter, icon, or arrow on the map for definition or see the legend.
© Gary P. Fleming | Original Image ⭷
© Bruce A. Sorrie | Original Image ⭷
© Bruce A. Sorrie | Original Image ⭷
© Erik Danielson source | Original Image ⭷
© Erik Danielson source | Original Image ⭷Feedback
See something missing or incorrect about Acorus calamus? Let us know here:
- Please include your name and if possible, email in case when need to clarify what you wrote.
- If you opt out of including email, please be as specific as possible (e.g., which photo is incorrect?)
- Please do not submit questions asking to identify plants or about horticultural topics (e.g., how do I control an invasive plant in my garden?). Instead, those questions can be submitted here for the Carolinas region only.
- Please do not send us feedback about unkeyed species as this work is ongoing.
- Please allow time for flora edits to show in our next data release. We greatly appreciate your feedback but may require extra time to research complicated taxonomic issues.
Horticultural Information
Intro: Stemless perennial found in marshes, wet meadows and other wet areas. Native of Eurasia, but now widespread in e. North America
Stems: Flowering stalk and leaves arise from a thick underground rhizome.
Leaves: Leaves 2-ranked and crowded basally, where they attach directly to the rhizome; linear and strap-like, to 70 in. long, with a prominent pink or red central vein and "crinkled" margins.
Inforescence:
Flowers: Flowers crowded in a stiff, linear-cylindric spike (2-4 in. long) that is attached at an angle near the middle of a long, leaf-like stem; greenish-yellow (later brownish), tiny.
Fruits:
Comments: Crushed leaves and rhizomes have a distinctive sweet smell; traditional uses of the rhizome range from medicinal to candy-making.
Height: 1-3 1/2 ft.
plant sale text:
bloom table text:
description: Stemless perennial found in marshes, wet meadows and other wet areas. Native of Eurasia, but now widespread in e. North America
stems: Flowering stalk and leaves arise from a thick underground rhizome.
leaves: Leaves 2-ranked and crowded basally, where they attach directly to the rhizome; linear and strap-like, to 70 in. long, with a prominent pink or red central vein and "crinkled" margins.
inflorescence:
flowers: Flowers crowded in a stiff, linear-cylindric spike (2-4 in. long) that is attached at an angle near the middle of a long, leaf-like stem; greenish-yellow (later brownish), tiny.
fruits:
comments: Crushed leaves and rhizomes have a distinctive sweet smell; traditional uses of the rhizome range from medicinal to candy-making.
cultural notes:
germination code:
native range: Europe & Asia
0 unsaved edits on this page.