Gentiana pennelliana

Fern.

Wiregrass Gentian

G3Vulnerable Found in 1 roadless area NatureServe Explorer →
G3VulnerableGlobal Rank
High - mediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.148193
Element CodePDGEN060K0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderGentianales
FamilyGentianaceae
GenusGentiana
Synonyms
Dasystephana tenuifolia(Raf.) Pennell
Other Common Names
wiregrass gentian (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.
Taxonomic Comments
When the species Dasystephana tenuifolia (Raf.) Pennell was transferred to Gentiana, the epithet tenuifolia was previously occupied so Fernald (1940) published Gentiana pennelliana "in recognition of Dr. Francis W. Pennell who in 1919 clearly established the specific distinctness."
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-04-07
Change Date1991-05-23
Edition Date2025-04-07
Edition AuthorsWhite, D.L. (1991), rev. Soteropoulos (2025)
Threat ImpactHigh - medium
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences21 - 80
Rank Reasons
Gentiana pennelliana is a perennial herb in sandy peat of moist to wet, open, wiregrass-dominated prairies, pineland savannas, flatwoods, and ecotonal seepage slopes endemic to the southeastern United States in the Florida Panhandle. It is intolerant of shade and is fire adapted, requiring a two to three year fire interval with most fires in the early part of the growing season to promote flowering. There are an estimated 61 occurrences which face threats from development, conversion of pine flatwoods to slash pine plantations, fire suppression, rights-of-way maintenance, recreational activities, and invasive species. Long-term declines may be as high as 54%. 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
Gentiana pennelliana is endemic to the southeastern United States in the Florida Panhandle where it can be found in the following counties: Bay, Calhoun, Franklin, Gadsden, Gulf, Leon, Liberty, Wakulla, Walton, and Washington (FNA 2023, FNAI 2023). Range extent was estimated to be 9,172 square kilometers using NatureServe Network occurrence data documented between 1994 and 2025 (NatureServe 2025, RARECAT 2025).
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 61 occurrences rangewide, excluding three occurrences that were failed to find in 2011 (NatureServe 2025, RARECAT 2025).
Threat Impact Comments
This species faces threats from habitat loss and degradation. Loss of habitat may be due to development or conversion of pine flatwoods to slash pine plantations, and the habitat is sensitive to drainage or degradation of the watershed (FNAI 2023). In plantations, G. pennelliana populations are destroyed when sites are mechanically prepared (Kral 1983).

The primary habitat degradation threats are fire suppression and rights-of-way maintenance. Fire suppression is likely to degrade existing habitat, increasing woody plant encroachment and possibly invasive species cover, and resulting in the possible loss of populations (FNAI 2023, NatureServe 2025). At least fourteen occurrences are located within roadside or powerline rights-of-way, and maintenance activities, such as herbicide and mowing, may negatively impact populations; however, mowing outside the flowering period may be beneficial to reduce woody plant encroachment (NatureServe 2025). Additional habitat degradation threats include recreational activities, as one occurrence is located adjacent to a golf course and a second had extensive off-road vehicle damage, invasive species, including black titi (Cliftonia monophylla), and droughts (NatureServe 2025).
Ecology & Habitat

Habitat

Gentiana pennelliana grows in sandy peat of moist to wet, open, wiregrass-dominated wet prairies, wet pineland savannas, wet flatwoods, ecotonal seepage slopes between flatwoods and titi swamps, slash pine plantations, and pineland clearings (Kral 1983, FNA 2023, FNAI 2023). Specifically, it is "found on black, humus or peat-enriched, constantly moist sands together with a wealth of grass and sedge species and a variety of savanna forbs. The overstory savanna species are mainly Slash Pine, Longleaf Pine, Pond Pine, occasional Pond Cypress, Nyssa biflora, Myrtle, Red Bay, Virginia Bay, Cyrilla, Cliftonia. It is usually in the grass-sedge zone bordering Hypericum ponds or Titi on the wet side, Longleaf Pine-Saw Palmetto-Wiregrass on the dry side" (Kral 1983).

Ecology

This species does best in sunlight (Kral 1983), and thus it is most often found in open habitats, which are historically maintained by fire. Gentiana pennelliana is a fire-adapted species; plants have a thickened root system which enables them to survive and resprout after burning (Kral 1983). Individuals observed after burns appeared more robust and healthier than those in unburned areas (Baker 1989). Flowering response may be related to fire frequency and season of burn. A profusion of flowering in November/December has been noted after a summer burn. The number of flowers observed decreased annually until the third season after burning, when no blooms were apparent (Baker 1989). It is not known if a growing-season burn is required for G. pennelliana to flower.
Terrestrial Habitats
Woodland - MixedSavannaGrassland/herbaceous
Palustrine Habitats
HERBACEOUS WETLANDFORESTED WETLAND
Other Nations (1)
United StatesN3
ProvinceRankNative
FloridaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentRestricted - smallSerious or 31-70% pop. declineModerate (short-term)
2 - Agriculture & aquacultureSmall (1-10%)Serious or 31-70% pop. declineModerate (short-term)
2.2 - Wood & pulp plantationsSmall (1-10%)Serious or 31-70% pop. declineModerate (short-term)
2.2.3 - Scale unknown/unrecordedSmall (1-10%)Serious or 31-70% pop. declineModerate (short-term)
4 - Transportation & service corridorsRestricted (11-30%)Serious - moderateHigh (continuing)
4.1 - Roads & railroadsRestricted (11-30%)Serious - moderateHigh (continuing)
4.2 - Utility & service linesSmall (1-10%)Serious - moderateHigh (continuing)
5 - Biological resource useRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
5.3 - Logging & wood harvestingRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
7 - Natural system modificationsRestricted (11-30%)Serious - moderateHigh (continuing)
7.1 - Fire & fire suppressionRestricted (11-30%)Serious - moderateHigh (continuing)
7.1.2 - Suppression in fire frequency/intensityRestricted (11-30%)Serious - moderateHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
8.1.1 - Unspecified speciesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
11 - Climate change & severe weatherUnknownUnknownUnknown
11.2 - DroughtsUnknownUnknownUnknown

Plant Characteristics
DurationPERENNIAL, WINTER-FLOWERING, SPRING-FLOWERING
Economic Value (Genus)No
Roadless Areas (1)
Florida (1)
AreaForestAcres
SavannahApalachicola National Forest1,927
References (14)
  1. Baker, Wilson. Personal communication. Biologist. Tall Timbers Research Station. Tallahassee, FL.
  2. Fernald, M.L. 1940. <i>Gentiana pennelliana</i>, nom. nov. Rhodora 42:198.
  3. Flora of North America Editorial Committee (FNA). 2023. Flora of North America north of Mexico. Vol. 14. Magnoliophyta: Gentianaceae to Hydroleaceae. Oxford Univ. Press, New York. xxiv + 505 pp.
  4. Florida Natural Areas Inventory (FNAI). 2023. Field Guide Account for Wiregrass Gentian <i>Gentiana pennelliana</i>. Online. Available: https://www.fnai.org/PDFs/FieldGuides/Gentiana_pennelliana.pdf (Accessed 2025).
  5. Godfrey, R.K., and J.W. Wooten. 1981. Aquatic and wetland plants of southeastern United States: Dicotyledons. Univ. Georgia Press, Athens. 933 pp.
  6. 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.
  7. Kral, R. 1983a. A report on some rare, threatened or endangered forest related vascular plants of the south. USFS technical publication R8-TP2, Atlanta, GA. Vol. 1: 718 pp.
  8. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  9. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  10. Streng, D. Tall Timbers Research Station. Tallahassee, Florida.
  11. Ward, D.B., ed. 1979. Rare and endangered biota of Florida. Vol. 5: Plants. Univ. Presses of Florida, Gainesville.
  12. 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).
  13. White, Deborah. Personal communication. Botanist, Kentucky Nature Preserves Commission, Frankfort, KY.
  14. Wunderlin, R.P. 1984. Endangered and threatened plant status survey. U.S. Fish and Wildlife Service, Contract No. 14c16c0004c79c100, Jacksonville, FL.