Sweet-flag - Acorus calamus

Alternative names
Sweet Flag

Medium to tall, tufted, rhizomatous plant. Leaves linear, pointed, rather Iris like. 7 to 20 mm wide, often with one or both margins crinkled, smelling sweetly when bruised. Flowers tiny, greenish yellow in a compact, narrow ascending cone 5 to 9 cm long, the stem prolonged above the flower cone into a leaf like spathe.

Identification difficulty

Rivers, canals and ponds.

When to see it

Flowers June and July.

Life History


UK Status

Widespread but rather local in Britain.

VC55 Status

Locally fairly frequent in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 49 of the 617 tetrads.

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map