About Tiarella nautila G.L.Nesom
Tiarella nautila G.L.Nesom is a perennial herbaceous plant with a short, slender rhizome. It produces a leafy flowering stem and relatively large basal leaves with an extended terminal lobe. The most defining characteristic of this species is its inability to form stolons. To positively identify Tiarella nautila, all of the following key features must be confirmed (in any order): stolons are always absent; basal leaves are usually longer than wide; basal leaf lobes are usually acute-acuminate, with the terminal lobe prominently extended; and the flowering stem usually has leaves or foliaceous bracts. If a plant has a stolon, it cannot be Tiarella nautila, and it is most likely either Tiarella stolonifera or Tiarella austrina. Apart from the characteristics of the flowering stem, the key identifying features of Tiarella nautila are identical to those of Tiarella wherryi, which makes distinguishing between the two species difficult. Similarly, except for the absence of stolons in Tiarella nautila, the two species share similar features with Tiarella austrina, which also creates identification challenges. Occasionally, Tiarella nautila produces a branched flowering stem. No other Tiarella species has this feature, so observing a branched flowering stem is sufficient to confirm the plant as Tiarella nautila. Tiarella nautila is narrowly endemic to the southeastern United States, occurring mainly in the southern Blue Ridge Mountains of northern Georgia, and adjacent areas of North Carolina and Tennessee. Confirmed counties where the species occurs are: in Georgia, Bartow, Cherokee, Cobb, Dawson, DeKalb, Fannin, Floyd, Forsyth, Gilmer, Hall, Jackson, Lumpkin, Murray, Pickens, Towns, Union, and White; in North Carolina, Cherokee; in Tennessee, Monroe and Polk. The ranges of Tiarella nautila and Tiarella austrina overlap in Dawson, Towns, and White counties in Georgia, Cherokee County in North Carolina, and Monroe County in Tennessee. The ranges of Tiarella nautila and Tiarella wherryi overlap in Bartow and Floyd counties in Georgia, and Monroe and Polk counties in Tennessee. The ranges of Tiarella nautila and Tiarella cordifolia overlap in Jackson County, Georgia.
