Cypripedium arietinum Ait. f.
Ram's Head Lady's Slipper
Facts About
Accepted Synonyms: Criosanthes arietina
Cypripedium arietinum, commonly known as Ram's Head Lady's Slipper, has a limited distribution across northeastern and central Canada and the U.S., from Quebec to Wisconsin. It has a distinctively conical and pointed labellum, which is white with reddish veins and covered with thin white hairs. The dorsal sepal curves to form a hood over the labellum, while the lateral petals and sepals, purple or green in color, form spirals which twist away from the pouch. It produces 3 to 5 blueish green leaves on its stems. Although this orchid is known to be pollinated by bees, it primarily reproduces vegetatively through offshoots from its rhizome, sometimes resulting in clusters of over a dozen plants in a single location. It grows in coniferous or mixed forests, swamps, and mossy bogs, often near cedar, spruce, or juniper trees.
Cypripedium arietinum is considered globally vulnerable, and is rare or endangered throughout much of its range.
Pollination
This orchid is pollinated by female halictid bees such as Lasioglossum coeruleum. The showy white and magenta flowers produce a sweet vanilla fragrance that attracts bees into the pouch formed by the labellum. The bee enter the flower and exits with pollen on its thorax.
Ecosystem Type
Bogs, forests, swamps
Characteristics
- Habitat:
- terrestrial
- Leaf arrangement:
- alternate
- Number of leaves on stem:
-
- three
- four
- five
- Form of the labellum:
- the labellum is pouch-like
- Labellum outline:
- the labellum is simple
- Main color of labellum:
- white
- Nectar spur:
- absent
- Inflorescence type:
- the inflorescence has one flower or a pair of flowers
- Labellum characteristics:
- the labellum is saccate
- Labellum length:
- 10–16 mm
- Sepal length:
- 15–25 mm
- Plant height:
- 10–35 cm
-
Flowers
- Floral bract length:
- 25–60 mm
- Flower petal color:
-
- brown
- green
- purple
- Flower symmetry:
- the flower is zygomorphic
- Flowering date:
-
- May
- June
- Flowers per inflorescence:
- 1–2
- Form of the labellum:
- the labellum is pouch-like
- Hairs on inflorescence axis:
- the inflorescence stem has at least some hairs with glands
- Inflorescence type:
- the inflorescence has one flower or a pair of flowers
- Labellum characteristics:
- the labellum is saccate
- Labellum length:
- 10–16 mm
- Labellum outline:
- the labellum is simple
- Labellum position:
- the flowers are resupinate
- Lower petal strongly red-veined:
- yes
- Main color of labellum:
- white
- Nectar spur:
- absent
- Number of stamens:
- 2
- Orientation of side petals:
-
- the lateral petals are declined
- the lateral petals are spreading
- Self-pollinating flowers:
- there are no cleistogamous flowers
- Sepal length:
- 15–25 mm
- Sepals fused only to sepals:
- the sepals are separate from one another
- Spots on labellum:
- no
-
Fruits or seeds
- Seed capsule orientation:
- the capsule points upwards or outwards
-
Growth form
- Plant height:
- 10–35 cm
- Roots:
- the rhizomes are non-coralloid
- Underground organs:
-
- slender roots
- this plant has a rhizome
- myco-heterotrophic or not:
- the plant is chlorophyllous
-
Leaves
- Bract relative length:
- the bract is longer than the associated flower
- Leaf arrangement:
- alternate
- Leaf blade edges:
- the leaf edges are entire
- Leaf blade length:
- 50–110 mm
- Leaf blade length to width ratio:
- 3.1–3.8
- Leaf blade shape:
-
- elliptic
- lanceolate
- Leaf blade tip:
-
- the tip of the leaf blade is acute
- the tip of the leaf blade is obtuse
- Leaf blade width:
- 13–35 mm
- Leaves during flowering:
- leaves are present during flowering
- Number of leaves on stem:
-
- three
- four
- five
-
Place
- Ecosystem type:
-
- bogs
- forests
- swamps
- Habitat:
- terrestrial
- Location:
-
- Connecticut
- Maine
- Manitoba
- Massachusetts
- Michigan
- Minnesota
- New Hampshire
- New York
- Nova Scotia
- Ontario
- Quebec
- Saskatchewan
- Vermont
- Wisconsin
-
Facts and Uses
- Mycorrhiza
- Monitoring
- Propagation
- Restoration
Native to North America
Yes
North American Conservation Status & Distribution
Conservation Status
Conservation and Wetland Status | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Canadian Status | May Be At Risk |
Conservation status for: Connecticut | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Connecticut Rank | N/A |
Connecticut Status | Species of Concern |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Massachusetts | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Massachusetts Rank | N/A |
Massachusetts Status | Endangered |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Manitoba | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Manitoba Rank | State Rare |
Manitoba Status | N/A |
Canadian Status | May Be At Risk |
Wetland Status | N/A |
Conservation status for: Maine | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Maine Rank | Highly State Rare |
Maine Status | Endangered |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Michigan | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Michigan Rank | Watch List |
Michigan Status | Species of Concern |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Minnesota | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Minnesota Rank | State Rare |
Minnesota Status | Threatened |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: New Hampshire | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
New Hampshire Rank | Highly State Rare |
New Hampshire Status | Endangered |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Nova Scotia | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Nova Scotia Rank | State Rare |
Nova Scotia Status | N/A |
Canadian Status | May Be At Risk |
Wetland Status | N/A |
Conservation status for: New York | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
New York Rank | State Rare |
New York Status | Threatened |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Ontario | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Ontario Rank | Watch List |
Ontario Status | N/A |
Canadian Status | May Be At Risk |
Wetland Status | N/A |
Conservation status for: Quebec | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Quebec Rank | Highly State Rare |
Quebec Status | N/A |
Canadian Status | May Be At Risk |
Wetland Status | N/A |
Conservation status for: Saskatchewan | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Saskatchewan Rank | State Rare |
Saskatchewan Status | N/A |
Canadian Status | May Be At Risk |
Wetland Status | N/A |
Conservation status for: Vermont | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Vermont Rank | State Rare |
Vermont Status | Threatened |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |
Conservation status for: Wisconsin | |
---|---|
Global Rank | Vulnerable |
US Status | N/A |
Wisconsin Rank | State Rare |
Wisconsin Status | Threatened |
Canadian Status | May Be At Risk |
Wetland Status | Facultative Wetland |