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Iris ensata — Russian iris

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Facts

Russian iris is native to China, Japan and eastern Russia, and is widely cultivated. There are a wide variety of cultivars, varying in flower color and form. Note that It has larger flowers than blue iris (Iris versicolor). Russian iris rarely escapes cultivation in North America, but in New England it has been collected from disturbed areas in Connecticut and Vermont.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Vermont
Leaf arrangement
  • alternate: there is one leaf per node along the stem
  • basal: the leaves are growing only at the base of the plant
Leaf blade shape
  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is linear (very narrow with more or less parallel sides)
Leaf blade length
300–800 mm
Flower petal color
  • blue to purple
  • white
Flower petal length
49–66 mm
Petal fusion
the perianth parts are fused to form a tube, cup, or bell shape
Inflorescence type
the inflorescence differs from the choices given
Ovary position
the ovary is below the point of petal and/or sepal attachment
Fruit type (specific)
the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
Fruit length
Up to 25 mm
Show all 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)
    Flower bracts
    there are bracts associated with the flower
    Flower number
    3–4
    Flower orientation
    the flowers point upward or spread or curve outward
    Flower petal color
    • blue to purple
    • white
    Flower petal length
    49–66 mm
    Flower shape
    the flower is another shape
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Form of style
    the style is branched above the base
    Fringed petal edges
    the petals are not fringed
    Inflorescence type
    the inflorescence differs from the choices given
    Length of flower stalk
    12–50 mm
    Marks on petals
    the petals have spots or streaks on them
    Nectar spur
    the flower has no nectar spurs
    Number of carpels
    3
    Number of pistils
    1
    Number of sepals and/or petals
    there are six petals, sepals or tepals in the flower
    Number of styles
    1
    Ovary position
    the ovary is below the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal base
    the petal narrows abruptly at the base
    Petal fusion
    the perianth parts are fused to form a tube, cup, or bell shape
    Sepal appearance
    the sepals resemble petals in color and texture
    Sepal length
    75–100 mm
    Sepal orientation
    • the sepals are curved outwards and downwards
    • the sepals are slightly curved outwards from the plant
    Sepals fused only to sepals
    the sepals are separate from one another
    Spathe
    • the plant does not have a spathe
    • the plant has a spathe surrounding the flower spike
    Spathe form
    NA
    Stamen number
    3
    Stamen position relative to petals
    the stamens are lined up with the sepals
    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 petal-like
    the style is broad and flattened like a petal
    Tepals
    the petals and sepals are similar in size and color
  • Fruits or seeds

    Berry color
    NA
    Fruit compartments
    there are three locules in the fruit
    Fruit cross-section
    the fruit is another shape in cross-section
    Fruit length
    Up to 25 mm
    Fruit type (general)
    the fruit is dry and splits open when ripe
    Fruit type (specific)
    the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
    Other markings on berry
    NA
  • Glands or sap

    Sap
    the sap is clear and watery
  • Growth form

    Lifespan
    the plant lives more than two years
    Underground organs
    the plant has a rhizome (a horizontal underground stem with roots growing from it)
  • 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
    the upper side of the leaf is not hairy, or has very few hairs
    Leaf arrangement
    • alternate: there is one leaf per node along the stem
    • 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 blade clasps the stem at the base, or the leaf blade goes all the way around the stem, so that the stem appears to pierce the leaf blade
    Leaf blade base shape
    the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    Leaf blade bloom
    the underside of the leaf blade has a 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
    300–800 mm
    Leaf blade orientation
    the edge of the leaf blade faces the stem of the plant
    Leaf blade shape
    • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the leaf blade is linear (very narrow with more or less parallel sides)
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade tip
    the tip of the leaf blade is acute (sharply pointed)
    Leaf blade veins
    the lateral veins are parallel or slightly arched in the direction of the tip
    Leaf blade width
    4–12 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
    terrestrial
    New England state
    • Connecticut
    • Vermont
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Scent

    Plant odor
    the leaves have no particular smell
  • Stem, shoot, branch

    Flowering stem growth form
    the flowering stem is held upright
    Flowering stem interior
    the flowering stem is solid
    Flowering stem leaves
    there is at least one fully-formed leaf on the flowering stem
    Stem hairs
    the stem is nearly or completely hairless

Wetland status

Not classified

In New England

Distribution

Connecticut
present
Maine
absent
Massachusetts
absent
New Hampshire
absent
Rhode Island
absent
Vermont
present

Conservation status

None

From Flora Novae Angliae dichotomous key

2.  Iris ensata Thunb. E

Russian iris. Iris kaempferi Sieb. ex Lemaire • CT, VT. Edges of lawns, fields, roadsides, compost heaps. Iris ensata has larger flowers than Iris versicolor (8–15 cm wide vs. 6–8 cm wide).

Native to North America?

No

Sometimes confused with

Iris sibirica:
flowers mostly 6–8 cm wide in life, capsules rounded-triangular in cross- section, lacking longitudinal ridges, and seeds D-shaped in outline (vs. I. ensata, with flowers 8–15 cm wide in life, capsules terete or nearly so in cross-section with 6 longitudinal ridges, and seeds +/- circular in outline).
Iris versicolor:
flowers mostly 6–8 cm wide in life, capsules rounded-triangular in cross- section, lacking longitudinal ridges, and seeds D-shaped in outline (vs. I. ensata, with flowers 8–15 cm wide in life, capsules terete or nearly so in cross-section with 6 longitudinal ridges, and seeds +/- circular in outline).

Synonyms

  • Iris kaempferi Sieb. ex Lemaire

Family

Iridaceae

Genus

Iris