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Home/Species/ Millboro Leatherflower

Clematis viticaulis

Steele

Millboro Leatherflower

G2Imperiled Found in 3 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
High - mediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.134546
Element CodePDRAN08110
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRanunculales
FamilyRanunculaceae
GenusClematis
Other Common Names
Millboro leather flower (EN)
Concept Reference
Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2026-02-13
Change Date2026-02-13
Edition Date2026-02-13
Edition AuthorsLudwig, J.C. (1991); rev. Ludwig/Maybury (1996); rev. Ludwig (Sept/97); rev. L. Morse (1998, 1999), rev. Soteropoulos (2026)
Threat ImpactHigh - medium
Range Extent100-250 square km (about 40-100 square miles)
Number of Occurrences6 - 20
Rank Reasons
Clematis viticaulis is a perennial, woody subshrub found in shale barrens and adjacent shaly woodlands. It is a narrow-ranging endemic in the southeastern United States in western Virginia where it has been documented in three counties in the Ridge and Valley physiographic province. There are ten estimated occurrences, which face threats from road widening and rights-of-way maintenance, logging and use of open habitat as a logging deck, competition, herbivory (deer and insect), recreational activities, work activities, invasive species, and drought. Several occurrences are located in George Washington National Forest. Monitoring of populations should be conducted to improve our understanding of reproduction, plant abundance, threats, and trends, as well as continuing conservation measures to protect the taxon.
Range Extent Comments
Clematis viticaulis is endemic to the southeastern United States in western Virginia where it has been documented in portions of Augusta (historic), Bath, and Rockbridge counties in the Ridge and Valley physiographic province (FNA 1997, Weakley and the Southeastern Flora Team 2025). Range extent was estimated to be 113 square kilometers using NatureServe Network occurrence data documented between 1994 and 2025 (RARECAT 2025, NatureServe 2026).
Occurrences Comments
By applying a 1 km separation distance to NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are ten occurrences rangewide (RARECAT 2025, NatureServe 2026).
Threat Impact Comments
This species faces threats from road widening and rights-of-way maintenance (herbicide), logging and use of open habitat as a logging deck, competition, herbivory (deer and insect), recreational activities (hunting), work activities (such as fire road upgrades and soil disturbance in open habitat), invasive species (including Crown Vetch and Japanese Stiltgrass), and drought (Southern Appalachian Species Viability Project 2002, NatureServe 2026).
Ecology & Habitat

Habitat

Clematis viticaulis grows in shale barrens and adjacent shaly woodlands, usually found on southern exposures, particularly toward the bases of slopes, developed from the Upper Devonian Brallier Formation (FNA 1997, Weakley and the Southeastern Flora Team 2025).

Reproduction

This species flowers from spring (May) to early summer (June) (FNA 1997, Weakley and the Southeastern Flora Team 2025).
Terrestrial Habitats
Forest/WoodlandWoodland - MixedBarrens
Other Nations (1)
United StatesN2
ProvinceRankNative
VirginiaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
4 - Transportation & service corridorsLarge (31-70%)Serious - moderateHigh (continuing)
4.1 - Roads & railroadsLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)
4.2 - Utility & service linesRestricted - smallModerate or 11-30% pop. declineHigh (continuing)
5 - Biological resource useLarge (31-70%)Moderate - slightHigh (continuing)
5.3 - Logging & wood harvestingLarge (31-70%)Moderate - slightHigh (continuing)
6 - Human intrusions & disturbanceUnknownUnknownHigh (continuing)
6.1 - Recreational activitiesUnknownUnknownHigh (continuing)
6.3 - Work & other activitiesLarge (31-70%)UnknownHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesUnknownUnknownHigh (continuing)
8.1.1 - Unspecified speciesUnknownUnknownHigh (continuing)
8.2 - Problematic native species/diseasesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8.2.2 - Named speciesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)

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Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (3)
Virginia (3)
AreaForestAcres
Beards MountainGeorge Washington National Forest7,505
Little AlleghanyGeorge Washington National Forest10,215
Mill MountainGeorge Washington National Forest10,840
References (10)
  1. Flora of North America Editorial Committee (FNA). 1997. Flora of North America north of Mexico. Vol. 3. Magnoliophyta: Magnoliidae and Hamamelidae. Oxford Univ. Press, New York. xxiii + 590 pp.
  2. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  3. Keener, C.S. 1967. A biosystemic study of Clematis subsection Integrifoliae (Ranunculaceae). J. Elisha Mitchell Scientific Society 83(1): 19-38.
  4. Kellifer, Steve. Botanist, Virginia Natural Heritage Program, Richmond.
  5. Kral, R. 1983c. A report on some rare, threatened, or endangered forest-related vascular plants of the South. U.S. Dept. of Agriculture Forest Service Technical Publication R8-TP2, Athens, GA. 1305 pp.
  6. Ludwig, Chris. Botanist, Virginia Division of Natural Heritage, Dept. of Conservation & Recreation, Main Street Station, Richmond, VA
  7. NatureServe. 2026. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  8. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  9. Southern Appalachian Species Viability Project. 2002. A partnership between the U.S. Forest Service-Region 8, Natural Heritage Programs in the Southeast, NatureServe, and independent scientists to develop and review data on 1300+ regionally and locally rare species in the Southern Appalachian and Alabama region. Database (Access 97) provided to the U.S. Forest Service by NatureServe, Durham, North Carolina.
  10. Weakley, A.S., and Southeastern Flora Team. 2025. Flora of the southeastern United States Web App. Edition of February 18, 2025. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. Online. Available: https://fsus.ncbg.unc.edu (accessed 2025).