Tridens flavus

(L.) A.S. Hitchc.

Tall Purple-top Fluffgrass

G5Secure Found in 8 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.135028
Element CodePMPOA65070
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderCyperales
FamilyPoaceae
GenusTridens
Synonyms
Triodia flava(L.) Smyth
Other Common Names
purpletop tridens (EN) Tall Redtop (EN) Trident jaune (FR)
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 Date2024-07-09
Change Date1984-09-06
Edition Date2024-07-09
Edition AuthorsEberly (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Tridens flavus is a wide ranging perennial grass occurring across the eastern United States and in northern Mexico. With a large range extent, more than 900 occurrences, broad habitat preferences and abundant habitat, and no obvious intrinsic vulnerabilities, this species is considered secure. There are two varieties which are sometimes elevated to the species level; variety chapmanii (syn. Tridens chapmanii) is more range limited and largely within the southeastern USA, as compared to var. flavus that occurs north to the New England states and south to northern Mexico.
Range Extent Comments
Tridens flavus occurs in the eastern United States from New Hampshire to Nebraska and south to Florida, Texas, and Nuevo León in northern Mexico (FNA2003a). It is considered non-native in Ontario, Canada and Vermont, USA. Range extent was estimated using herbarium specimens and photo-based observations documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024). There are two varieties which are sometimes elevated to the species level; variety chapmanii (syn. Tridens chapmanii) is more range limited and largely within the southeastern USA, as compared to var. flavus that occurs north to the New England states and south to northern Mexico.
Occurrences Comments
By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1993 and 2024, there are estimated to be over 900 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024). See the assessment for each variety for more information.
Ecology & Habitat

Habitat

This species grows on a variety of dry to moist soils with varying pH levels in full sun to shade of woods, glades, barrens, and meadows and often in disturbed areas or sites with eroded soils, like roadsides (Foote and Jackobs 1966, FNA 2003a, Brakie and Shadow 2021, Weakley and Southeastern Flora Team 2024).
Terrestrial Habitats
Forest/WoodlandForest EdgeGrassland/herbaceousOld fieldBarrensCropland/hedgerowSuburban/orchard
Other Nations (2)
CanadaNNA
ProvinceRankNative
OntarioSNANo
United StatesN5
ProvinceRankNative
GeorgiaS5Yes
VermontSNANo
MissouriSNRYes
OklahomaSNRYes
TennesseeSNRYes
KansasSNRYes
VirginiaSNRYes
IowaS4Yes
DelawareS5Yes
New MexicoSNRYes
AlabamaSNRYes
TexasSNRYes
KentuckyS5Yes
ConnecticutSNRYes
North CarolinaS5Yes
MassachusettsSNRYes
IllinoisS5Yes
New YorkS5Yes
West VirginiaS5Yes
New JerseySNRYes
New HampshireSNRYes
MarylandSNRYes
MinnesotaSNRYes
LouisianaSNRYes
South CarolinaS5Yes
Rhode IslandSNRYes
OhioS5Yes
FloridaSNRYes
WisconsinSNRYes
PennsylvaniaS5Yes
District of ColumbiaSNRYes
MississippiSNRYes
NebraskaSNRYes
MichiganSNRYes
IndianaS5Yes
ArkansasSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined

Plant Characteristics
DurationPERENNIAL, Short-lived
Economic Value (Genus)No
Roadless Areas (8)
Arkansas (2)
AreaForestAcres
Blue MountainOuachita National Forest9,755
Little BlakelyOuachita National Forest3,342
North Carolina (1)
AreaForestAcres
Woods MountainPisgah National Forest9,602
Texas (2)
AreaForestAcres
Little Lake CreekNational Forests in Texas596
Winters BayouNational Forests in Texas730
Virginia (2)
AreaForestAcres
Brush MountainJefferson National Forest6,002
Little AlleghanyGeorge Washington National Forest10,215
West Virginia (1)
AreaForestAcres
Middle MountainMonongahela National Forest19,020
References (8)
  1. Brakie, M., and A. Shadow. 2021. Plant Guide for purpletop (<i>Tridens flavus</i>). USDA-Natural Resources Conservation Service, East Texas Plant Materials Center. Nacogdoches, TX.
  2. Flora of North America Editorial Committee (FNA). 2003a. Flora of North America north of Mexico. Vol. 25. Magnoliophyta: Commelinidae (in part): Poaceae, part 2. Oxford Univ. Press, New York. xxv + 781 pp.
  3. Foote, L.E., and J.A. Jackobs. 1966. Occurrence and stand density of <i>Tridens flavus</i> (L.) Hitchc. as related to some soil factors. Agronomy Journal 58:412-414.
  4. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  5. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  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. Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).
  8. Weakley, A.S., and Southeastern Flora Team. 2024. Flora of the southeastern United States. Edition of March 4, 2024. University of North Carolina Herbarium (NCU), North Carolina Botanical Garden, University of North Carolina, Chapel Hill. 2203 pp.