Northeast Wetland Flora
Field Office Guide to Plant Species
Acorus calamus L.
- Family: Aroid (Araceae)
- Flowering: May-August
- Field Marks: The distinguishing features of this species are its iris-like flattened leaves, leaf midvein off-centered on the blade, sweet-smelling rhizomes and leaves, and its single spike of flowers borne partway up the flat stem.
- Habitat: Wet areas.
- Habit: Perennial herb from sweet-smelling rhizomes.
- Stems: Upright, leaf-like, flattened, smooth, up to 3 feet tall, without leaves but bearing a single spike part-way up.
- Leaves: Basal, linear, flat, iris-like, smooth, sweet-smelling, up to 3 feet long, up to 1 inch broad, with the midvein off-centered.
- Flowers: Numerous, crowded in an elongated spike (spadix), the spike up to 4 inches long, up to 3/4 inch thick, borne part-way up the leaf-like stem.
- Sepals: 3, small, brownish yellow, concave.
- Petals: 3, small, brownish yellow, concave.
- Stamens: 6.
- Pistils: Ovary superior, smooth.
- Fruits: Numerous in a spike, crowded, dry, but containing gelatinous pulp and 1-3 seeds.
- Notes: The sweet-smelling rhizomes have reputed medicinal properties. Gleason and Cronquist place this species in the Acoraceae.
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