Cypripedium arietinum

R. Brown

in W. Aiton and W. T. Aiton, Hortus Kew. 5: 222. 1813

Common names: Ram’s-head
Treatment appears in FNA Volume 26. Treatment on page 501. Mentioned on page 499.
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.

Phenology: Flowering May–Jun.
Habitat: Dry to moist open coniferous and mixed forests, coniferous-forested fens, beach thickets
Elevation: mostly 0–400 m


V26 1019-distribution-map.jpg

Man., N.S., Ont., Que., Sask., Conn., Maine, Mass., Mich., Minn., N.H., N.Y., Vt., Wis.




Lower Taxa

No lower taxa listed.