Rams-head ladyslipper

Rams-head ladyslipper, Cypripedium arietinum,  is a distinctive orchid in the family Orchidaceae. Rams’s head lady’s slipper derives its name from the sac-like shape of its lip petal which resembles the head of a charging ram. Unlike many other orchids, Rams-head lady’s slipper doesn’t grow in trees, instead, it can be found growing gracefully on the forest floor. This orchid is rare and is currently listed on the New York State Department of Environmental Conservation rare species list.


Rams-head ladyslipper grows in cool, moist woodlands and coniferous forests are found growing near tamaracks, spruce and cedar trees. It is distributed throughout the central and northeastern United States, particularly the Great Lakes region, and can also be found in central and eastern Canada.


Flower: The most distinctive attribute of the Rams-head ladyslipper is its flower bloom which is divided laterally at its sepals with an inverted conical shaped lower petal that is covered with fine white hairs. The bloom resembles the head of a charging ram and is crimson red in color with a white lip.

Stem/Leaves: Stems grow to about 30 cm in length and have usually 3 to 5 narrow pointed leaves per stem. Leaves wavy margins and grow to be 5-10 cm long. Both the stem and leaves have tiny glandular hairs. 

Fun Facts: 

The rams-head ladyslipper requires the pollination of small bees to accomplish cross-pollination; once fertilization has occurred the upper saple of this orchid closes over the opening in the lower lip to keep other pollinators from entering. Reproduction can also occur through the production of offshoots from parent plants.  The flowering of the rams-head orchid doesn’t always occur annually, some individuals only flower every other year. Germination of seeds only occurs in the presence of a compatible fungal partner forming a symbiotic relationship among the fungi and root system of the plant. The specific reproductive needs of the rams-head lad slipper paired with habitat loss have contributed to the rarity of this beautiful orchid species.

Photo Credits: 

All photos found at: (fs.fed.us).


“Meet The Ladies: The Slipper Orchids.” Fs.fed.us. United States Department of Agriculture Forest Service, n.d. Web. 19 Aug. 2015. <http://www.fs.fed.us/wildflowers/beauty/cypripedium/cypripedium_arietinum.shtml>.
“Rams-head Lady’s-slipper Photos and Facts.” Arkive.org. Widescreen Archive, n.d. Web. 19 Aug. 2015. <http://www.arkive.org/rams-head-ladys-slipper/cypripedium-arietinum/>.


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