Tiarella nautila
Nesom
Sail-bearing Foamflower
G3VulnerableGlobal Rank
UnknownThreat Impact
Tom Kennedy, CC BY 4.0
dogbowlbookpile, CC BY-NC 4.0
dogbowlbookpile, CC BY-NC 4.0
Sequoia Janirella Wrens, CC BY-NC 4.0
Identity
Unique IDELEMENT_GLOBAL.2.1300949
Element CodePDSAX10060
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRosales
FamilySaxifragaceae
GenusTiarella
Concept Reference
Nesom, G.L. 2021. Taxonomy of Tiarella (Saxifragaceae) in the eastern USA. Phytoneuron 31: 1-61.
Taxonomic Comments
Nesom (2021) splits the broad concept of Tiarella cordifolia recognized by Flora of North America Editorial Committee (2009) into five species. T. stolonifera is a stoloniferous species that is widespread from Michigan to the northeastern U.S. and adjacent Canada and south into Kentucky, Tennessee, and montane Virginia and North Carolina (Nesom 2021). Tiarella cordifolia following Nesom (2021) is a non-stoloniferous species, on the eastern seaboard from Maryland to Georgia. The other three eastern species of Tiarella recognized by Nesom (2021) are restricted to the southeastern U.S: T. austrina, T. wherryi, and T. nautila.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-08-22
Change Date2024-08-22
Edition Date2024-08-22
Edition AuthorsSoteropoulos (2024)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences21 - 300
Rank Reasons
Tiarella nautila is a perennial herb in forests and on rock outcrops in the southeastern United States in the Southern Blue Ridge of extreme southwestern North Carolina, extreme southeastern Tennessee south to north-central Georgia. Delimiting distribution and abundance would benefit from careful review of herbarium specimens and photo-based observations. 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
Tiarella nautila occurs in the southeastern United States in the Southern Blue Ridge of extreme southwestern North Carolina, extreme southeastern Tennessee south to north-central Georgia (Weakley and the Southeastern Flora Team 2024). Range extent was estimated to be approximately 25,000 square kilometers using herbarium specimens and photo-based observations documented between 1993 and 2024 (iNaturalist 2024, SEINet 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens and photo-based observations documented between 1993 and 2024, it is estimated that there are between 55 and 150 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024). Due to different treatments of this entity as a recent segregate from T. cordifolia, herbarium records and photo-based observations may underrepresent true abundance.
Threat Impact Comments
Although threats are not widely documented, this species is potentially threatened by development, logging, recreational activities, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species.
Ecology & Habitat
Habitat
Tiarella nautila grows in "moist forests, cove forests, rock outcrops, well-drained bottomland forests" (Weakley and the Southeastern Flora Team 2024).
Terrestrial Habitats
Forest/WoodlandForest - HardwoodForest - MixedBare rock/talus/scree
Other Nations (1)
United StatesN3
| Province | Rank | Native |
|---|---|---|
| North Carolina | S1 | Yes |
| Tennessee | SNR | Yes |
| Georgia | SNR | Yes |
Threat Assessments
| Threat | Scope | Severity | Timing |
|---|---|---|---|
| Unknown/undetermined | — | — | — |
Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (3)
Georgia (3)
| Area | Forest | Acres |
|---|---|---|
| Helton Creek | Chattahoochee National Forest | 2,348 |
| Pink Knob | Chattahoochee National Forest | 12,127 |
| Rocky Mountain | Chattahoochee National Forest | 4,269 |
References (4)
- iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
- Nesom, G.L. 2021. Taxonomy of <i>Tiarella </i>(Saxifragaceae) in the eastern USA. Phytoneuron 31: 1-61.
- Southwest Environmental Information Network (SEINet). 2024. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2024).
- 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.