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- Cypripedium arietinum
Cypripedium arietinum — ram's-head lady's-slipper
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Facts
The small but dramatic ram's-head lady's-slipper is rare and protected throughout New England. It flowers early, in mid May to early June, and flowers last only a week or so. Most individuals in a population do not flower in a given year.
Habitat
Forests, swamps
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Number of leaves on stem
-
- five
- four
- three
- Form of lower petal
- the labellum has a pouch-like shape
- Lower petal outline
- the labellum is simple in form
- Main color of lower petal
-
- green to brown
- 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
- Lower petal length
- 10–16 mm
- Sepal length
- 15–25 mm
-
Flowers
- Flower petal color
-
- brown
- green
- red
- 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 inflorescence axis
-
- NA
- at least some of the hairs on the main stem of the inflorescence have glands
- the main stem of the inflorescence has hairs entirely without glands
- Inflorescence type
- the inflorescence has only one flower or a pair of flowers on it
- Labellum position
- the labellum is in the lower position on the flower
- Length of narrowed base of lower petal
- 0 mm
- Lobes at base of lower petal
- 0 mm
- Lower petal characteristics
- the labellum is in the shape of a pouch
- Lower petal length
- 10–16 mm
- Lower petal outline
- the labellum is simple in form
- Lower petal strongly red-veined
- yes
- Main color of lower petal
-
- green to brown
- white
- Nectar spur
- there are no nectar spurs on the flower
- Nectar spur length
- 0 mm
- Number of stamens
- 2
- Orientation of side petals
-
- the lateral petals slant outward
- the lateral petals slant somewhat downward
- Pollen sacs
- NA
- Self-pollinating flowers
- there are no cleistogamous flowers on this plant
- Sepal length
- 15–25 mm
- Sepals fused only to sepals
- the sepals are separate from one another
- Shape of viscidium
- NA
- Spots on lower petal
- no
- Spur opening membrane
- NA
- Spur opening shape
- NA
-
Fruits or seeds
- 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 do not resemble coral
- Underground organs
-
- there are only slender roots on the plant
- this plant has a rhizome (a horizontal underground stem with roots growing from it)
-
Leaves
- Bract relative length
-
- the bract is longer than the associated flower
- the bract is shorter than the associated flower
- Features of leaves
-
- the leaf does not have any of the mentioned special features
- the leaf is pleated or folded back and forth along its length
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade edges
- the edges of the leaf blade have no teeth
- Leaf blade length
- 50–110 mm
- Leaf blade length to width ratio
- 3.1–3.8
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both ends)
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the leaf blade is oblong (rectangular but with rounded ends)
- 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 acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf blade width
- 13–35 mm
- Leaves during flowering
- there are leaves on the plant when it is flowering
- Number of bracts on stem
- 0
- Number of leaves on stem
-
- five
- four
- three
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- forests
- swamps
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- 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.
- Connecticut
- historical (S-rank: SH), special concern, extirpated (code: SC*)
- Maine
- extremely rare (S-rank: S1), endangered (code: E)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
- Vermont
- rare (S-rank: S2), threatened (code: T)
From Flora Novae Angliae dichotomous key
2. Cypripedium arietinum Ait. f. NC
ram’s-head lady’s-slipper. CT, MA, ME, NH, VT. Deciduous and mixed evergreen-deciduous forests, often on enriched soils due to bedrock influence or colluvial deposits, also in swamps dominated by Thuja occidentalis.
Native to North America?
Yes