Calypso bulbosa (L.) Oakes

fairy-slipper

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Fairy-slipper is a rare orchid in New England, being found only in northern white-cedar (Thuja occidentalis) dominated swamps in Maine, New Hampshire and Vermont. The generic name (Calypso) comes from Homer's sea-nymph in the Odyssey who kept Odysseus concealed seven years on her island. The Thompson Indians of British Columbia chewed the corms and sucked on the flowers to treat mild epilepsy.

Habitat

Swamps

Characteristics

Habitat
wetlands
New England state
  • Maine
  • New Hampshire
  • Vermont
Leaf arrangement
basal: the leaves are growing only at the base of the plant
Number of leaves on stem
absent
Form of lower petal
the labellum has a pouch-like shape
Lower petal outline
the labellum is lobed but not fringed
Main color of lower petal
  • pink to red
  • white
Nectar spur
there are no nectar spurs on the flower
Inflorescence type
the inflorescence has only one flower or a pair of flowers on it
Lower petal characteristics
  • the labellum is in the shape of a pouch
  • the labellum is lobed
Lower petal length
13–23 mm
Sepal length
10–24 mm
Show All Characteristics
  • Flowers
    Flower petal color
    • purple
    • white
    Flower symmetry
    there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
    Flowering date
    • June
    • May
    Flowers per inflorescence
    1–2
    Form of lower petal
    the labellum has a pouch-like shape
    Hairs on flower stalk
    NA
    Hairs on inflorescence axis
    NA
    Inflorescence length
    35–50 mm
    Inflorescence type
    the inflorescence has only one flower or a pair of flowers on it
    Inflorescence width
    30–40 mm
    Labellum position
    the labellum is in the lower position on the flower
    Length of narrowed base of lower petal
    0 mm
    Length of peduncle
    100–200 mm
    Lobes at base of lower petal
    0 mm
    Lower petal characteristics
    • the labellum is in the shape of a pouch
    • the labellum is lobed
    Lower petal length
    13–23 mm
    Lower petal outline
    the labellum is lobed but not fringed
    Lower petal strongly red-veined
    no
    Main color of lower petal
    • pink to red
    • white
    Nectar spur
    there are no nectar spurs on the flower
    Nectar spur length
    0 mm
    Number of stamens
    1
    Orientation of side petals
    the lateral petals are angled steeply upwards
    Self-pollinating flowers
    there are no cleistogamous flowers on this plant
    Sepal length
    10–24 mm
    Sepals fused only to sepals
    the sepals are separate from one another
    Shape of viscidium
    the viscidium is another shape than the choices given
    Spots on lower petal
    yes
    Spur opening membrane
    NA
    Spur opening shape
    NA
  • Fruits or seeds
    Fruit length
    20–30 mm
    Fruit width
    10–15 mm
    Length of peduncle when in fruit
    0 mm
    Seed capsule orientation
    the capsule points upwards or is angled outwards
  • Growth form
    Plant green or not
    the plant is chlorophyllous (it has green parts)
    Roots
    the rhizomes are branched and resemble coral
    Underground organs
    • the plant has one or more swollen storage organs underground, such as bulbs, tubers or corms
    • there are only slender roots on the plant
  • Leaves
    Bract relative length
    the bract is shorter than the associated flower
    Features of leaves
    the leaf is pleated or folded back and forth along its length
    Leaf arrangement
    basal: the leaves are growing only at the base of the plant
    Leaf blade edges
    the edges of the leaf blade have no teeth
    Leaf blade length
    10–65 mm
    Leaf blade length to width ratio
    0.8–1.3
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is orbicular (roughly circular, as wide as long)
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    Leaf blade tip
    • the tip of the leaf blade is acuminate (tapers to a long, thin point)
    • the tip of the leaf blade is acute (sharply pointed)
    • the tip of the leaf blade is obtuse (bluntly pointed)
    Leaf blade width
    12–52 mm
    Leaves during flowering
    there are leaves on the plant when it is flowering
    Number of bracts on stem
    2–3
    Number of leaves on stem
    absent
  • Place
    Habitat
    wetlands
    New England state
    • Maine
    • New Hampshire
    • Vermont
    Specific habitat
    swamps

Wetland Status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

New England Distribution and Conservation Status

Distribution

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

Conservation Status

Exact status definitions can vary from state to state. For details, please check with your state.

Maine
uncommon to fairly widespread (S-rank: S3S4)

ssp. americana

New Hampshire
historical (S-rank: SH), endangered (code: E)

var. americana

Vermont
extremely rare (S-rank: S1), threatened (code: T)

Native to North America?

Yes

Sometimes Confused With

Cypripedium arietinum:
labellum lacking a pair of apical horns and also without evident yellow bristles, and plants with 3 or 4 leaves borne on a stem (vs. C. bulbosa, with labellum with a pair of yellow, apical horns and also with evident, yellow bristles, and plants with single basal leaf).
Cypripedium acaule:
labellum lacking a pair of apical horns and also without evident yellow bristles, and plants with a pair of basal leaves (vs. C. bulbosa, with labellum with a pair of yellow, apical horns and also with evident, yellow bristles, and plants with a single basal leaf).

Synonyms

  • Calypso bulbosa (L.) Oakes var. americana (R. Br. ex Ait. f.) Luer

Family

Orchidaceae

Genus

Calypso

Notes on Subspecies and Varieties in New England

Our subspecies is ssp. americanus (R. Br. ex Ait. f.) A. Haines

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Information from Dichotomous Key of Flora Novae Angliae

1.  Calypso bulbosa (L.) Oakes ssp. americana (R. Br. ex Ait. f. ) A. Haines NC

fairy-slipper. Calypso bulbosa (L.) Oakes var. americana (R. Br. ex Ait. f.) Luer; Cypripedium bulbosum L., pro parte; Cytherea bulbosa (L.) House, pro parteME, NH, VT. Evergreen swamps dominated by Thuja occidentalis.