Cypripedium arietinum R.Br.
  • Hortus Kew.
  • Ram’s-head

Cite taxon page as 'WFO (2021): Cypripedium arietinum R.Br. Published on the Internet; Accessed on: 02 Dec 2021'

General Information

Plants erect, 10–35 cm. Leaves 3–4, along middle portion of stem, spiraled to alternate, ascending to spreading; blade narrowly elliptic to ovate-lanceolate or oblong, 5–11 × 1.3–3.5 cm. Flowers usually solitary (rarely 2 in forma biflorum P. M. Brown); sepals green with reddish brown markings; dorsal sepal broadly elliptic to ovate-lanceolate, 15–25 × 5–10 mm; lateral sepals distinct, 12–20 × 1.5–4 mm; petals somewhat spreading, same color as sepals, somewhat spirally twisted, linear- to linear-lanceolate, 11–24 × 1–2 mm; lip white with green apex, usually with extensive reddish reticulations often merging toward apex, adaxially swollen near middle, 10–16 mm, apex abruptly deflected downward, orifice basal, 7–12 mm; staminode suborbicular. 2n = 20.

  • Provided by: [B].Flora of North America @
    • Source: [
    • 1
    • ]. 

    "Stem slender, 1–4 dm, thinly hairy, with 2–3 sheathing scales below and 3–5 sessile lvs above the middle; lf-blades lanceolate to elliptic, often folded, 5–10 cm, finely ciliate, otherwise glabrous; fl solitary; sep and lateral pet 1.5–2.5 cm, greenish-brown, the upper sep lanceolate, the lower 2 sep separate, linear, the lateral pet lance-linear; lip whitish, strongly red-veined, 1.5–2.5 cm, prolonged downward to form a conical pouch. Moist, usually acid soils in coniferous woods; Que. to Man., s. to Mass., N.Y., Mich. and Minn. May, June."

  • Provided by: [A].New York Botanical Garden
    • Source: [
    • 2
    • ]. 

    Other Local Names



     Information From

    New York Botanical Garden
    Descriptions of plants should be attributed to the full citation for each individual article, chapter or book that is the source for each record, which should include the authors of original publication.
    • A Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
    Flora of North America @
    'Flora of North America @ eFloras (2008). Published on the Internet [accessed August 2016]' Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
    • B Flora of North America Association
    International Union for Conservation of Nature v.3
    IUCN 2019. The IUCN Red List of Threatened Species. Version 2019-1.
    • C See IUCN Terms and conditions of use
    International Union for Conservation of Nature
    IUCN 2016. IUCN Red List of Threatened Species. Version 2016-2
    • D All Rights Reserved
    • E CC0 1.0 Universal (CC0 1.0).
    World Flora Online consortium
    World Flora Online Data. 2018.
    • F CC0 1.0 Universal (CC0 1.0).