Cypripedium kentuckiense is found in a narrow range from the Cumberland Plateau of Kentucky and northern Tennessee; the Interior Highlands of Arkansas, Missouri, and Oklahoma; and the Gulf Coastal Plain of Texas, Louisiana, Alabama, and Mississippi.
This species is found in the following states, counties, and types of geographic regions (which give a more accurate representation of range than states because the species occupies such a small area compared to its total range):
- Alabama: Coosa, Hale, Lowndes, Sumter (East Gulf Coastal Plain and Piedmont )
- Arkansas: Boone, Clark, Crawford, Franklin, Garland, Grant, Hempstead, Howard, Jefferson, Johnson, Lincoln), Madison, Montgomery, Perry, Pike, Polk, Pulaski, Saline, Sevier, Yell (Boston and Ouachita Mountains of Ozark Region of the Interior Highlands and upper West Gulf Coastal Plain)
- Kentucky: Jackson, Knox, Laurel, Lee, Lewis, McCreary, Owsley, Pulask, Rowan, Wolfe (Northeastern Bluegrass Subsection of Bluegrass Section of Interior Low Plateaus)
- Tennessee: Decatur, Franklin, Scott (Cumberland Plateau Section of Unglaciated Appalachian Plateaus)
- Virginia: Lancaster
- Georgia: Laurens
- Texas: Newton, Red River, Sabine, San Augustine (Upper West Gulf Coastal Plain)
- Louisiana: Bienville, Bossier, Catahoula, De Soto, Evangeline, Grant, Jackson, Lincoln, Natchitoches, Ouachita, Rapides, Red River, Sabine, Union, Vernon, Winn (Upper West Gulf Coastal Plain )
- Oklahoma: Choctaw, Le Flore, McCurtain, Pushmataha (Upper West Gulf Coastal Plain and Ouachita Mountains of Interior Highlands )
- Mississippi: Clay, Lee (Upper West Gulf Coastal Plain)
The extent of occurrence (EOO) is estimated at 882,010 km² and the area of occupancy (AOO) is estimated at 748 km².
The species can be found up to 500 m altitude.
Sources: Atwood 1985, Chafin et al. 2007, Cribb 1997, Frosch and Cribb 2012, Kartesz 1994, Morse 1981.
Regularity: Regularly occurring
Global Range: Cypripedium kentuckiense is found on the Cumberland Plateau of Kentucky and northern Tennessee; the Tennessee Uplands; the Interior Highlands of Arkansas, Oklahoma, and potentially Missouri (many sites in the Ouachita Mountains and some in the Ozark Mountains); the Piedmont and Gulf/Upper Gulf Coastal Plains of Alabama and the Gulf Coastal Plain of Texas, Louisiana, and Mississippi (Oklahoma Natural Heritage Inventory 2001, A. Schotz, pers. comm., 2002). Also occurs disjunctly on the Atlantic Coastal Plain of Virginia and Georgia (T. Patrick, pers. comm., 2002).
Catalog Number: US 3274283
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): C. F. Reed
Year Collected: 1949
Locality: Elliot, Kentucky, United States, North America
- Holotype: Reed, C. F. 1981. Phytologia. 48: 426.
Habitat and Ecology
This species is found in mesic woodlands near bodies of water, often on the floodplains of streams. It is more restricted to floodplains in Kentucky and Tennessee, but its habitat is more variable in the rest of its range and it may be found on floodplains, ravines, and acidic-seep forests in Arkansas, slash pine forests in Louisiana, and forested springhead seeps in Georgia (CPC Plant Profile). It is most often associated with American beech and white oak forests (Allen 2004). Although this has not been documented, the scattered nature of the population distributions suggests that this species may be limited by mycorrhizal specificity or a rarely encountered soil composition (Marilyn Light pers. comm.).
Cypripedium kentuckiense prefers moist, acid sandstone soils. The species grows from shaded to semi-shaded and flowers in May-June.
Its pollinators have not been definitively identified, but they are suspected to be bees, which are frequent pollinators of other Cypripedium species. Germinating seeds have been shown to associate with soil fungi, which the mature plant may also require to grow. This species is prey for deer and other herbivores. Where its range overlaps with a closely related Cypripedium species, C. pubescens, it is competitively excluded from slope forest habitats and restricted to floodplains (CPC Plant Profile).
Comments: Mesic, shaded areas in mature floodplain forests, near streams and creeks (e.g., sandy stream terraces on flats right above active floodplain) and in ravines. Also associated with woodland acid spring seeps, where often found on seepage margins (Ouachita National Forest 2001), and with forested limestone seeps adjacent to bayheads (T. Patrick, pers. comm., 2002).
Known Pests: Feral hogs are a known threat to this orchid. Overbrowsing by deer is also a threat (Chafin 2007).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: Approximately 100-200 occurrences are believed extant (about 100 confirmed extant and 100 not yet assessed). Approximately half of these occurrences are in Arkansas, with significant numbers in Kentucky, Tennessee, and Louisiana as well, and the remainder scattered throughout the rest of range. An additional 19 occurrences are considered historical or extirpated.
Life History and Behavior
IUCN Red List Assessment
Red List Category
Red List Criteria
Although distributed over quite a wide area, most populations of Cypripedium kentuckiense are quite small; approximately 100-200 occurrences are believed extant, but less than 30 of these may have good viability.
The last extensive population estimate for the entire species was done in 1996 by Weldy et al. (1996) which placed the total species population size at 4,343 individuals. There was evidence of a continuing decline from 1951 to 1985, because Medley reports a 50% population decline from 1951-1985 that resulted in a 1985 population estimate of 2,683 individuals (Nilles 2006).
The area of occupancy of C. kentuckiense (748 km2) is well below the 2,000 km2 threshold, the population is severely fragmented and the species and its habitats are under numerous threats especially collection, overgrazing, deforestation, disturbance by feral hogs, infrastructure development, loss of habitat due to logging, pine agriculture, and reservoir construction which cause a continuing decline of the species across its range and even the destruction of some subpopulations. This species therefore meets the requirements for listing as as Vulnerable (VU).
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: Cypripedium kentuckiense occurs in a somewhat narrow range from the Cumberland Plateau of eastern Kentucky and northern Tennessee with outlier populations in central Georgia and Coastal Plain Virginia, west to the Interior Highlands of Arkansas and southeastern Oklahoma, and south to the Gulf Coastal Plain of Texas, Louisiana, Alabama, and Mississippi. Its moderate range is somewhat misleading as most sites/populations are quite small; approximately 100-200 occurrences are believed extant, but less than 30 of these may good viability. Collection is a significant threat with many incidents of poaching documented. Other threats include herbivory by white-tailed deer, disturbance by feral hogs, road construction, and habitat destruction due to logging, pine agriculture, and reservoir construction. This species' habitat has been considerably reduced from its historical extent. Believed to be moderately declining in Arkansas and significantly declining in Kentucky; these two states contain the majority of extant occurrences. However, occurrences in some other parts of the range appear to be stable.
There are currently between 81 and 233 occurrences of Cypripedium kentuckiense; this is somewhat misleading as most sites/subpopulations are quite small; approximately 100-200 occurrences are believed extant, but less than 30 of these may have good viability.
There are 156 subpopulations and 4,343 individuals according to the latest census in 1996. The average subpopulation size is 40 and ranges from 1- 450, but 58% of subpopulations have less than 21 individuals and 43% have less than 10 (Weldy et al. 1996).
In terms of abundance, most states classify this species as SI, which is critically imperiled (less than five occurrences or very steep declines), while in Tennessee it is ranked S2 (imperiled- less than 20 occurrences or steep declines) and in Arkansas it is ranked S3 (vulnerable- less than 80 occurrences or recent declines) (CPC Plant Profile). The number of mature individuals in these subpopulations is unknown.
Oklahoma populations are restricted to four southeastern counties: McCurtain, Leflore, Choctaw, and Pushmataha.
Global Short Term Trend: Decline of 30-50%
Comments: Poulations fluctuate widely year-to-year, making trends difficult to determine. In Arkansas, some sites appear to be "thriving" (Ouachita National Forest 2001), but the species is estimated to be moderately declining overall; collection/poaching is a serious threat and road construction is an issue (T. Witsell, pers. comm., 2006, 2010). The status is apparently improving in Oklahoma (Oklahoma Natural Heritage Inventory 2001). East Texas occurrences appear to be fairly stable; and most are on protected lands (J. Poole and J. Singhurst, pers. comm. 2010). It is in considerable decline (> 50%) in population size and extent throughout its range in Kentucky; no Kentucky populations have been increasing (D. White, pers. comm., 2002, 2010). One of the five known Alabama populations (all of them small) recently fell victim to plant poachers (A. Schotz, pers. comm., 2002). The Georgia site appears to be a young population slowly expanding, with several juveniles scattered some distance from a half dozen clustered flowering plants (T. Patrick, pers. comm., 2002).
Global Long Term Trend: Decline of 50-90%
Comments: Considerable loss of this species' historical habitat has occurred rangewide. In Arkansas, Ouachita river terraces habitat has been greatly reduced from its historical extent (T. Witsell, pers. comm. 2010). There has also been significant habitat loss in east Texas and Louisiana, where it is estimated that less than 20-30% of this species' historical habitat remains (J. Poole and J. Singhurst, pers. comm. 2010). In Kentucky, historical habitat loss is estimated to exceed 50% (D. White, pers. comm. 2010).
This species is most threatened by habitat destruction, which is most often due to clear-cutting logging practices or forestry practices, which convert hardwood stands to planted pine, and changes in stream hydrology caused by logging, reservoir construction, or shifting land use. Populations that occur on protected state or federal land are most threatened by collecting, which is not illegal in all states (NatureServe 2011). The collected plants are sold or kept as ornamental plants, or sometimes used in alternative medicine as an immunity booster. Deer and wild hog grazing is a severe threat in some areas (Georgia) but not in others (Texas, Alabama) (Tom Patrick, Michael Eason and Al Schotz pers. comms.).
The species also has some inherent growth and reproduction characteristics that inhibit its population growth. It is documented to have low rates of germination, high seed-adult mortality, and a long development time, as well as high rates of dispersal that tend to create isolated populations very easily. A genetic analysis of the species has shown that genetic diversity is comparable to that of species endemic to a very small range, which is very low for a species of this wide of a range and suggests there has been a population bottleneck at some point (Case et al. 1998). This low diversity may create inbreeding depression in these populations, which could cause the production of the especially small fruits that have been observed. This could also be due to low pollinator availability, low pollinator travel range- as typical for bees associated with Cypripedium- or poor pollen quality, but these aspects have not been researched (Marilyn Light pers. comm.).
Degree of Threat: Very high - high
Comments: Collection is a significant threat. Cypripedium kentuckiense is actively collected for sale (D. White, pers. comm. 2002) and pressure to raid natural populations may be increasing, even though the species is advertised by several nurseries as available laboratory-propagated (T. Patrick pers. comm., 2002). Serious collection pressure exists in Arkansas, with documented incidents of poaching (T. Witsell, pers. comm. 2006, 2010). The Georgia site is treated as confidential and access has been restricted to avoid unauthorized plant collection (T. Patrick, pers. comm. 2002). Herbivory by white-tailed deer is another serious threat across many parts of the range, and disturbance by feral hogs is an issue in a number of areas. In addition, road/highway construction is a threat in many areas, both the actual construction taking place on a site where the plants occur and the resultant changes in hydrology over a wider area (Tennessee Natural Heritage Program 2001, D. White, pers. comm. 2002, T. Witsell pers. comm. 2010). Also threatened by other types of habitat destruction such as logging, pine agriculture, and reservoir construction (Oklahoma Natural Heritage Inventory 2001). At the Georgia site, logging of hardwoods and conversion to pine monoculture is an imminent threat (T. Patrick, pers. comm. 2002). In Texas, some sites contain no reproductive individuals, likely because Texas represents a relict area of distribution for this species (J. Poole and J. Singhurst pers. comm. 2010).
This species is listed as a federal species of concern, but this status does not make it subject to any federal protection or legislation under the Endangered Species Act. It is protected internationally under CITES Appendix II, which requires export and import permits for trade. Under the NatureServe conservation ranking it is ranked on a state level as S1 (critically imperiled) in most states in its range, S2 (imperiled) in Tennessee, and S3 (vulnerable) in Arkansas (NatureServe 2011). Under this same scale it has a global status of G3 (vulnerable; NatureServe 2011) because of its wide range. Legal protection depends on the individual states. Kentucky, Texas, Georgia, Tennessee, Virginia, and Mississippi have state endangered species acts or equivalent plant-specific legislature. However, this legislation does not require the identification of critical habitats or the development of recovery plans in all states, and in Tennessee and Kentucky there is no law against collecting rare plants on public or private land. Also, in Kentucky, populations on private land are not under any legal protection at all. In Alabama, Oklahoma, and Arkansas there is no state endangered species legislation, and this species has no legal protection at all. In Arkansas, Kentucky, Louisiana, Texas, and Oklahoma most of the species distribution is found in state park areas and none or almost none is in Alabama, Georgia, Virginia, Tennessee, and Mississippi. There have been active efforts to increase population size through propagation and replanting in Louisiana and Georgia. Seeds were collected, artificially propagated, and resulting plants planted in Louisiana in 2006 (Nilles 2006).
Preserve Selection and Design Considerations: This is a wetland plant which tolerates some flooding. Maintenance of the natural flood regime for the creeks where the populations occur is an important part of site conservation planning.
Relevance to Humans and Ecosystems
Production Methods: Cultivated, Wild-harvested
Comments: Cypripedium kentuckiense is propagated and grown by several nurseries which specialize in orchid propagation. Collection of wild plants continues to be a threat.
Stewardship Overview: Protection of habitat of the population is important. This includes control of exotic plants, and feral hogs which may root up these rare plants. Population enhancement by seed collection, nursery propagation, and reintroduction of nursery grown seedlings back to the same site the seed was collected is a promising approach.
Originally thought to be an aberrant form of Cypripedium parviflorum var. pubescens, the morphology of C. kentuckiense suggests it is a species of its own. However, molecular evidence suggests that C. kentuckiense is actually closer to Cypripedium parviflorum var. parviflorum than it is to Cypripedium parviflorum var. pubescens.
C. kentuckiense has the largest flower of in the genus Cypripedium. The petals and sepals are greenish striped and mottled with purple while the very large lip, or pouch, is a creamy ivory or pale yellow. The plant can be up to 70 cm tall and has bract leaf-like leaves that are up to 12 cm long. Each plant is usually single-flowered.
Cypripedium kentuckiense is found in a large swathe through the central portion of the United States including Texas, Mississippi, Kentucky, Ohio, Missouri, Arkansas, Oklahoma, Louisiana, and Tennessee. Additionally, there is a small patch in Lancaster County, Virginia. However, the range of this species is not continuous; it mostly consists of relatively isolated patches. It is most often found in deep ravines on acidic and sandstone soils.
- Phillip Cribb & Peter Green (1997). The Genus Cypripedium (a botanical monograph). Kew Royal Botanic Gardens, Timber Press ISBN 0-88192-403-2
- Case, M.A, H.T. Mlodozeniec, L.E. Wallace, and T.W. Weldy. 1998. Conservation genetics and taxonomic status of the rare Kentucky Lady's Slipper: Cypripedium kentuckiense (Orchidaceae). American Journal of Botany, vol. 85, num. 12: 1779-1786
Cypripedium kentuckiense is very distinctive. In addition to the very large flowers and pale coloring of the lip, the form of the orifice is unique. In related species the orifice is a restricted opening in the adaxial surface of the lip; in C. kentuckiense the orifice replaces the basal portion of the adaxial surface, the sides of the lip terminating abruptly at the orifice without curving toward the horizontal. In herbarium specimens this detail is obscured, but the cavernous nature of the orifice is emphasized by the adaxial surface descending from the apical margin of the orifice toward the apex of the lip; the obovoid lip appears to hang from the margin of the orifice, and the lip is not particularly slipper-shaped. In contrast, in related species, the adaxial surface of the lip surrounds the orifice and extends forward toward the apex, forming a more convincing slipper. These distinctions hold virtually throughout the known populations of C. kentuckiense; only in two Arkansas populations is the lip form suggestive of related species. The Arkansas populations may reflect very limited introgression from C. parviflorum var. pubescens.
Names and Taxonomy
Comments: Cypripedium kentuckiense was recognized as a distinct species in the 1970s; it was formerly confused with various other members of the Cypripedium calceolus group. Isozyme data suggest that Cypripedium kentuckiense should be recognized as a distinct species, possibly of recent origin from Cypripedium parviflorum (Case et al. 1998).
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