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• Acorus calamus

Acorus calamus — single-veined sweetflag

Facts

Because single-veined sweetflag has three sets of chromosomes, it is sterile and cannot produce fruit. European settlers brought it to North America and grew it for medicinal purposes. It propagates readily through spread of the rhizomes, and has spread throughout the eastern and midwestern United States, with scattered instances elsewhere. The rhizome has medicinal properties and has been used to treat a variety of conditions from nausea, heartburn, and colds to fatigue and anxiety.

Habitat

Lacustrine (in lakes or ponds), marshes, riverine (in rivers or streams), shores of rivers or lakes, wetland margins (edges of wetlands)

Characteristics

• Clonal plantlets

  Axillary bulblets

  there are no bulblets being produced in axils

• Flowers

  Anther attachment

  the anther is attached by its base to the filament

  Anther color

  the anthers show no hint of a pink, reddish or purplish tint

  Bulblets replace flowers

  there are no bulblets where the flowers are located

  Carpels fused

  the carpels are fused (the number of carpels equals the number of locules)

  Filament surface

  the filament surface has no hairs or scales on it

  Flower bract length

  15–90 mm

  Flower bracts

  there are bracts associated with the flower

  Flower orientation

  the flowers point upward or spread or curve outward

  Flower petal color

  • green to brown
  • yellow

  Flower petal length

  3–4 mm

  Flower shape

  the flower has a tube-shaped corolla

  Flower symmetry

  there are two or more ways to evenly divide the flower (the flower is radially symmetrical)

  Form of style

  the style is knob-like at the tip, and unbranched

  Fringed petal edges

  the petals are not fringed

  Hairs on flower stalk

  NA

  Inflorescence hair glands

  the axis of the inflorescence has no hairs on it

  Inflorescence length

  38–89 mm

  Inflorescence type

  the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)

  Inflorescence width

  5.3–10.8 mm

  Length of flower stalk

  0 mm

  Length of peduncle

  150–500 mm

  Marks on petals

  there are no noticeable marks on the petals

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  2–3

  Number of pistils

  1

  Number of sepals and/or petals

  there are six petals, sepals or tepals in the flower

  Number of styles

  0–1

  Ovary position

  the ovary is above the point of petal and/or sepal attachment

  Petal and sepal arrangement

  the flower includes only one cycle of petals or sepals

  Petal appearance

  the petals are green and/or leafy in texture

  Petal base

  the petal narrows gradually or does not narrow at the base

  Petal fusion

  the perianth parts are separate

  Petal hairs on inner/upper surface

  there are no hairs on the inner/upper petal surface

  Petal nectaries

  the petals do not have nectaries

  Sepal appearance

  the sepals resemble leaves in color and texture

  Sepal length

  3–4 mm

  Sepal orientation

  the sepals are pressed against the plant, or jutting stiffly upward

  Sepals fused only to sepals

  the sepals are separate from one another

  Spathe

  the plant does not have a spathe

  Spathe form

  NA

  Spathe length

  0 mm

  Stamen length

  1.7–2.9 mm

  Stamen number

  6

  Stamen position relative to petals

  NA

  Stamen types

  the stamens within a cycle are all similar

  Stamens fused

  the stamens are not fused to one another

  Stamens fused outwards

  the stamens are not fused to the petals or tepals

  Style length

  At least 0 mm

  Style petal-like

  the style is not broad and flattened like a petal

  Tepals

  the petals and sepals are similar in size and color

• Fruits or seeds

  Berry color

  • NA
  • brown
  • green

  Capsule ridges

  NA

  Fruit beak length

  0 mm

  Fruit cross-section

  the fruit is round in cross-section

  Fruit length

  0 mm

  Fruit stalk orientation

  NA

  Fruit type (general)

  • NA
  • the fruit is fleshy

  Fruit type (specific)

  • NA
  • the fruit is a berry (fleshy, with the wall enclosing one or more sections, with two or more seeds)

  Fruit width

  0 mm

  Other markings on berry

  • NA
  • the ripe fruits are mostly one color without spots or streaks
  • the ripe fruits have spots or streaks on them

• Glands or sap

  Sap

  the sap is clear and watery

• Growth form

  Lifespan

  the plant lives more than two years

  Root septa

  the roots do not have transverse septa

  Underground organs

  • the plant has a rhizome (a horizontal underground stem with roots growing from it)
  • there are only slender roots on the plant

• Leaves

  Hairs on underside of leaf blade

  the underside of the leaf is not hairy, or has very few hairs

  Hairs on upper side of leaf blade

  NA

  Leaf arrangement

  basal: the leaves are growing only at the base of the plant

  Leaf blade basal lobes

  the leaf blades do not have basal lobes

  Leaf blade base

  the leaf has no stalk

  Leaf blade base shape

  NA

  Leaf blade bloom

  the underside of the leaf blade has no noticeable waxy or powdery bloom

  Leaf blade cross-section

  the leaf blade is more or less flat in cross-section

  Leaf blade faces

  the surfaces of the leaf blade are composed of tissues from the abaxial side only

  Leaf blade form

  Fully-formed (i.e., expanded), +/- green leaf blades are found somewhere on the plant

  Leaf blade length

  299–1750 mm

  Leaf blade orientation

  the edge of the leaf blade faces the stem of the plant

  Leaf blade shape

  the leaf blade is linear (very narrow with more or less parallel sides)

  Leaf blade surface colors

  • NA
  • the upper side of the leaf blade is relatively uniform in color

  Leaf blade tip

  the tip of the leaf blade is acuminate (tapers to a long, thin point)

  Leaf blade veins

  the lateral veins are parallel or slightly arched in the direction of the tip

  Leaf blade width

  5–20 mm

  Leaf stalk length

  0 mm

  Leaf type

  the leaves are simple (i.e., lobed or unlobed but not separated into leaflets

  Leaflet number

  0

  Stipule twining

  NA

  Stipules

  there are no stipules on this plant

• Place

  Habitat

  • aquatic
  • wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • edges of wetlands
  • in lakes or ponds
  • in rivers or streams
  • marshes
  • shores of rivers or lakes

• Scent

  Plant odor

  the leaves smell of lemon, citrus or other fruit

• Stem, shoot, branch

  Flowering stem growth form

  • the flowering stem is held upright
  • the flowering stem trails along the ground or on other vegetation, or floats in the water

  Flowering stem leaves

  there are no true leaves on the flowering stem

  Stem hairs

  the stem is nearly or completely hairless

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae