Cypripedium parviflorum

Cypripedium parviflorum, commonly known as yellow lady's slipper[4] or moccasin flower,[5] is a lady's slipper orchid native to North America.[3] It is widespread, ranging from Alaska south to Arizona and Georgia.[6] It grows in fens, wetlands, shorelines, and damp woodlands.[7]

Cypripedium parviflorum
Cypripedium parviflorum var. makasin
Mackinac Island, Michigan

Secure (NatureServe)[2]
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Cypripedioideae
Genus: Cypripedium
C. parviflorum
Binomial name
Cypripedium parviflorum
  • Cypripedium luteum var. parviflorum (Salisb.) Raf.
  • Criosanthes parviflora (Salisb.) Raf.
  • Calceolus parviflorus (Salisb.) Nieuwl.
  • Cypripedium calceolus var. parviflorum (Salisb.) Fernald
  • Cypripedium hirsutum var. parviflorum (Salisb.) Rolfe
  • Cypripedium bulbosum var. parviflorum (Salisb.) Farw.
  • Cypripedium calceolus subsp. parviflorum (Salisb.) Hultén


  • Plant: 16 to 60 cm tall, reported to 80 cm elswhere: stem, bracts, and leaves pubescent; flower stem rises 10 cm above leaves; one flower, rarely two.
  • Roots: few to many slender roots to 4 cm long on jointed rhizome.
  • Leaves: ovate lanceolate, cauline, plicate, four to six on blooming plants, from 9 ⨉ 4 cm to 14 ⨉ 5 cm; covered with fine hairs on underside; a few hairs on topside.
  • Floral bracts: ovate lanceolate bract at base of ovary, 7 ⨉ 2 cm.
  • Flowers: bright yellow pouch with greenish to reddish sepals and petals; up to 10 cm high ⨉ 10 cm wide.
  • Sepals: yellowish green with reddish stripes that turn to dots near pouch, fine hairs on back and edges; dorsal sepal ovate lanceolate, slightly concave, 4 ⨉ 2.2 cm; synsepal ellipitic, slightly concave; slight notch at tip, 3.2 ⨉ 1.4 cm.
  • Petals: linear, acute, yellowish green with reddish stripes that turn to dots at pouch; 5.5 cm long ⨉ 0.7 cm wide; fine hairs on back along well-defined central ridge; few hairs on inner one-third toward pouch.
  • Lip: bright yellow obovoid (pouch- or slipper-shaped), 3.2 cm wide ⨉ 4.0 cm high; opening 1.2 ⨉ 2.0 cm, with incurved margin; red dotted stripes on veins and faint reddish dots on inside and back of pouch.
  • Column: light green with red dots at base, 1.5 cm high; two fertile anthers, one to either side; staminode yellow with red dots, arrowhead-shaped, with V form (folded); pollinia yellow sticky masses.
  • Capsule: ellipsoidal, pubescent, 2.2 to 3 cm long ⨉ 0.6 to 1.3 cm in diameter


C. parviflorum is a highly variable species, which is a result of both hybridization and phenotypic plasticity.[8]

Four varieties are widely recognized. They are:[9]

  • C. parviflorum var. exiliens SheviakAlaska
  • C. parviflorum var. makasin (Farwell) Sheviak – commonly called the "northern yellow lady's-slipper";[10] widely distributed over much of Canada and the northern United States
  • C. parviflorum var. parviflorum – commonly called the "small yellow lady's-slipper";[11] southern part of the species range, from eastern Nebraska and eastern Oklahoma east to Virginia and New Hampshire
  • C. parviflorum var. pubescens (Willdenow) O. W. Knight – commonly called the "large yellow lady's-slipper";[11] very widespread across much of United States, Canada, and St. Pierre & Miquelon; treated by many authors as a distinct species, Cypripedium pubescens

Distribution and HabitatEdit


  • Newfoundland to British-Columbia, south to Georgia, Arizona, and Washington; Europe.
  • Newfounland to Alaska and south to Oregon in the West.
  • In the East along the Atlantic Coast, it is in every state except Florida and extends across to Louisiana and eastern Texas.
  • New Mexico state: Catron, Colfax, Grant, Los Alamos, Otero, San Miguel, San Juan and Santa Fe Counties.
  • Arizona state: Apache, Graham, and Greenlee Counties.


  • A more upland plant preferring subacidic to neutral soils.
  • Primarily in mesic to dry-mesic upland forests, woodlands with deep humus or layers of leaf litter, shaded boggy habitats, but also in hill prairies and occasionally in wetlands with organic, well-drained, sandy soils.
  • Moderate shade to nearly full sun in fir, pine, and aspen forest between 6000 and 9500 feet (1830 and 2900 meters).
  • Mountain meadows and on timbered slopes.
  • Dripping seeps on steep to moderately sloped canyon walls.


  1. ^ Arditti, J., Michaud, J.D. and Healey, P.L. 1979. Morphometry of orchid seeds. I. Paphiopedilum and native California and related species of Cyprideum. American Journal of Botany 66(10): 1128.
  2. ^ Arditti, J., J. D. Michaud and P. L. Healey. 1979. Morphometry of orchid seeds. I. PAPHIOPEDILUM and native California and related species of CYPRIPEDIUM. American Journal of Botany 66(10):1128-1137.
  3. ^ a b "Cypripedium parviflorum". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  4. ^ "Cypripedium parviflorum". Go Botany. New England Wildflower Society.
  5. ^ Voitk, Andrus; Voitk, Maria (2006). Orchids on the Rock: The Orchids of Newfoundland. Rocky Harbour, NL: Gros Morne Co-operating Association.
  6. ^ "Cypripedium parviflorum distribution map". Flora of North America.
  7. ^ "Burke Herbarium Image Collection". Retrieved 2022-07-15.
  8. ^ Sheviak, Charles J. (2002). "Cypripedium parviflorum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford – via, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  9. ^ "Cypripedium parviflorum". North American Orchid Conservation Center (NAOOC), Smithsonian Environmental Research Center. 2018.
  10. ^ "Northern Yellow Lady's-slipper (Cypripedium parviflorum var. makasin)". Wisconsin Department of Natural Resources.
  11. ^ a b Weakley, Alan (2015). "Flora of the Southern and Mid-Atlantic States". Archived from the original on 2018-10-06. Retrieved 2018-01-23.

External linksEdit