Vascular Plants of North Carolina
Account for Carolina Alumroot - Heuchera caroliniana   Rosendahl, Butters, & Lakela
Members of Saxifragaceae:
Members of Heuchera with account distribution info or public map:
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Section 6 » Order Rosales » Family Saxifragaceae
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AuthorRosendahl, Butters, & Lakela
DistributionEssentially restricted to the Piedmont, but absent from the northeastern quarter. Ranges eastward only to Rockingham, Randolph, and Moore counties; ranges westward to the foot of the Blue Ridge Escarpment. The edges of the range are slightly unsettled owing to the great similarity of the species with H. americana; no surprise, in that H. caroliniana was pulled out from that species as a new species. The range map below is based essentially on specimens at NCU, which is probably the only reliable herbarium for this genus. It is suspected that most herbaria still have records of this species named as H. americana.

This species has a very narrow range, being a Piedmont endemic; it ranges from south-central VA, through central NC, and south to north-central SC.
AbundanceFairly common to common, at least in the central band of the range, from Surry and Stokes counties south to Gaston, Mecklenburg, Union, and Anson counties. Perhaps uncommon farther west toward counties bordering the southern Blue Ridge Escarpment, and along the eastern edge of the range. Note that the very similar H. americana occurs over much of the range of this species, and thus identification in the field can be difficult. The NCNHP considers it as a Watch List species, as W7 (poorly known). However, the editors suggest a W1 status (rare but relatively secure) is better. Note that the Global Rank is only G3, because of its very small range, and thus it does seem wise to at least keep some type of records on it in the state.
HabitatIt occurs in the same, if not identical, habitats of H. americana -- generally mesic but often rocky soils that are either circumneutral or just slightly acidic. It prefers full to partial shade, and is most often found in open upland forests, rocky woods, along wooded borders, and around the margins of outcrops.
PhenologyBlooms from April to June, and fruits shortly flowering.
IdentificationThis is a "standard" alumroot, looking essentially like the very familiar H. americana, with which it was subsumed until recently elevated to full species status. It has several basal leaves on long petioles, and each leaf blade is somewhat rounded with a cordate base; the blade is somewhat split into several lobes and with clearly serrated margins. The separate flowering stalk grows to about 2-2.5 feet tall, with the inflorescence occupying the top 6-12 inches. The flowers, scattered along this stalk, have a hemi-spherical calyx, as opposed to an urn-shaped or bell-shaped calyx in the very similar H. americana. In H. americana, the stamens extend about 3 mm or more beyond the calyx, and the styles also extend about 2-3 mm beyond the calyx when in flower; however, in H. caroliniana the stamens extend barely 1 mm beyond the calyx and the styles the same. Thus, H. caroliniana has flowers that barely show the tips of the stamens and styles, as opposed to clearly showing a few millimeters of them with the other species. These are very detailed characters that take the joy out of simply enjoying these species, even if the flowers are not colorful but are a pale white. The flowers tend to be drooping in these species, as opposed to spreading horizontally in H. acerifolia. Also beware that in leaf, this species is very similar to Foamflower (Tiarella cordifolia), which has a much more attractive and dense white panicle of flowers when in bloom. Normally, Tiarella grows in richer soil on lower slopes and can occur in moderate stands, whereas Heuchera species generally grow only singly or in small groups and on drier or rockier sites, though both can occur in the same general area. You may be safe simply identifying H. caroliniana by its range -- as long as you are in the western or central Piedmont -- but it is always good to check the floral characters, if these are available. Look at both the shape of the calyx and the length of the male and female parts -- this species will have a more rounded look to the rear of the flower and very little of the stamens and pistils extending beyond the petals.
Taxonomic CommentsAs mentioned above, this species was mainly considered as a variety of H. americana -- as H. americana var. caroliniana -- or simply included within it. Most major references do consider it as a valid species now, including NatureServe.

Other Common Name(s)None
State RankS3
Global RankG3
State StatusW7 [W1]
US Status
USACE-agcp
USACE-emp
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