Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: Alaska to Nova Scotia, south to Nebraska and Georgia. This is a widespread species complex whose taxonomy is being revised. The global range of the subspecies found in Alaska cannot now be determined with confidence from the literature.
Petals conspicuously twisted, pouch small, 2-2.5 cm, sepals and petals deep reddish brown.
Comments: Rich, humus and decaying leaf litter in wooded areas, often on rocky wooded hillsides on north or east facing slopes, also wooded loess river bluffs. Moist creeksides or swales in spruce zones, soils sandy loams to loams.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: This is a widespread species complex whose taxonomy is being revised. The global occurrence of the subspecies found in Alaska cannot now be determined with confidence from the literature.
Constant moisture very important during germination and early development.
Life History and Behavior
Persistence: PERENNIAL, Long-lived, DECIDUOUS
Molecular Biology and Genetics
Statistics of barcoding coverage: Cypripedium parviflorum
Public Records: 4
Specimens with Barcodes: 4
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
Relevance to Humans and Ecosystems
Comments: Rootstock yielded the drug cypridpedium, which was used as an official nerve stimulant.
Four varieties are widely recognized:
- Cypripedium parviflorum var. makasin (Farwell) Sheviak - widely distributed over much of Canada and the northern USA
- Cypripedium parviflorum var. parviflorum - southern part of the species range, from eastern Nebraska and eastern Oklahoma east to Virginia and New Hampshire
- Cypripedium parviflorum var. pubescens (Willdenow) O. W. Knight - very widespread across much of USA, Canada, and St. Pierre & Miquelon - treated by many authors as a distinct species, Cypripedium pubescens
The southeastern var. parviflorum differs from var. pubescens primarily in flower size and color, and the two might be merely forms. Most works dealing with Cypripedium parviflorum have treated the primarily boreal var. makasin as var. parviflorum, either including all small-lipped plants within var. parviflorum, or in some cases restricting the name to the northern variety and excluding the southeastern plants described by Salisbury as C. parviflorum. Fernald’s original publication on C. calceolus var. parviflorum actually treated var. makasin, citing a description of that variety and clearly discussing the northern plant. Additionally, although geographically accommodating Salisbury’s plant, Fernald excluded most of the range of the southeastern var. parviflorum, thereby referring most plants of var. parviflorum to var. pubescens, and further restricted var. pubescens to the east, thereby assigning most plants of that variety to his northern var. parviflorum, i.e., var. makasin. Consequently, most published illustrations of var. parviflorum are in fact var. makasin. Variety parviflorum has been dealt with primarily in publications on the southeastern flora. In the east, var. makasin is quite distinct, but in the west it becomes difficult to separate from very small plants of var. pubescens that are common there; in that area, fragrance is often the least equivocal character. In the northwest it seems to merge with C. × columbianum, and in fact the northwestern elements of the species are only artificially accommodated within the variety. Very rarely plants apparently referable to var. makasin or var. parviflorum bear white lips. In some cases that may reflect past gene flow, but in others the plants appear to be color forms.
Hybrids of Cypripedium parviflorum with C. candidum are C. × andrewsii A. M. Fuller, and different varietal parentages are recognized as nothovar. andrewsii [C. candidum × C. parviflorum var. makasin], nothovar. favillianum (J. T. Curtis) B. Boivin [C. candidum × C. parviflorum var. pubescens], and nothovar. landonii (Garay) B. Boivin [C. parviflorum var. parviflorum × C. × andrewsii nothovar. favillianum]. Hybrids of C. parviflorum with C. montanum are C. × columbianum Sheviak; the type was evidently derived from a cross with var. pubescens. Hybrids of var. pubescens commonly exhibit small lips and thus obscure varietal limits: in the northwest, C. × columbianum merges with var. makasin and var. pubescens; in the midwest, C. × andrewsii nothovar. favillianum may simulate var. parviflorum, and the delimitation of those two entities is unclear. Additionally, many plants of putative C. × andrewsii nothovar. favillianum suggest C. × columbianum. In general, those hybrids exhibit vegetative and floral morphology and color intermediate between those of their parents, or combinations of their parental characteristics. In particular, lips are commonly creamy, ivory, or yellow; often lips are yellow when the flower first opens and fade to white over the period of bloom. Consequently, different flowers on the same plant frequently exhibit a range of lip colors. Lip color furthermore sometimes varies from year to year in individual plants. Additionally, C. montanum and C. parviflorum var. makasin commonly contribute the dark coloration of their sepals and petals to hybrids with C. parviflorum and C. candidum, respectively. The apical margin of the orifice in C. candidum and C. montanum is typically acute, forming a sharp angle directed toward the apex of the lip. In C. parviflorum, this is a variable feature, but typically the margin is obtuse. Variation in this feature in yellow-lipped plants may in some circumstances aid the recognition of hybrids.
Names and Taxonomy
Comments: The yellow lady's slippers are often considered to be three distinct species, Cypripedium calceolus being strictly Eurasian and the American plants being assigned to either C. parviflorum or C.pubescens (sometimes treated as varieties of C. calceolus). Kartesz (1999) treats the North American plants in this group as three varieties of broadly viewed species called Cypripedium parviflorum (vars. makasin, parviflorum, and pubescens); in 1994, he had treated them as two species, C. parviflorum and C. pubescens, not addressing "var. makasin" which only recently received new recognition. Another, questionably distinct entity, "planipetalum", has been variously treated as a species (e.g., by Kartesz, 1994), as a variety or subspecies of C. calceolus or C. parviflorum, or as a synonym of one of the more generally recognized taxa. Yet another entity, the species Cypripedium kentuckiense, was recognized about 1980 and is now generally accepted as distinct; these plants had previously been confused with one or more of the species in the parviflorum/pubescens group. As presented here, following the Kartesz (1999) treatment, Cypripedium parviflorum is viewed broadly, with varieties makasin, parviflorum, and pubescens. "Cypripedium parviflorum" of Kartesz (1994) corresponds to "C. parviflorum var. parviflorum" as presented here. LEM 28Feb01.
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