About Tiarella austrina (Lakela) G.L.Nesom
Tiarella austrina (Lakela) G.L.Nesom is a perennial herbaceous plant with a short, slender rhizome, a leafy flowering stem, and relatively large basal leaves that have an extended terminal lobe. A defining characteristic of this species is its ability to produce stolons.
To positively identify Tiarella austrina, all of the following key features must be verified in any order: a stolon is present; basal leaves are usually longer than wide; basal leaf lobes are usually acute-acuminate, with the terminal lobe prominently extended; the flowering stem usually has 1–2 leaves or foliaceous bracts. These key features are similar to those of Tiarella nautila, but the presence of a stolon rules out Tiarella nautila.
In eastern North America, Tiarella austrina is narrowly endemic to the southeastern United States, where it occurs mainly in the southern Blue Ridge Mountains of southwestern North Carolina, southeastern Tennessee, northeastern Georgia, and northwestern South Carolina. Confirmed county occurrences are as follows: Alabama: Jackson, Madison; Georgia: Dawson, Habersham, Rabun, Stephens, Towns, White; North Carolina: Buncombe, Cherokee, Clay, Graham, Haywood, Henderson, Jackson, Macon, Polk, Swain, Transylvania; South Carolina: Greenville, Oconee, Pickens; Tennessee: Blount, Cocke, Franklin, Monroe, Sevier.
The ranges of Tiarella austrina and Tiarella nautila overlap in Georgia (Dawson, Towns, White), North Carolina (Cherokee), and Tennessee (Monroe). Both Tiarella austrina and Tiarella stolonifera occur in Buncombe County, North Carolina. A small disjunct population of Tiarella austrina overlaps with Tiarella wherryi in northeastern Alabama (Jackson, Madison) and adjacent south-central Tennessee (Franklin).
