Vascular Plants of North Carolina
Account for Threepart Violet - Viola tripartita   Elliott
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Section 6 » Order Violales » Family Violaceae
AuthorElliott
DistributionScattered over the mountains, and the western and central Piedmont, east to Rockingham, Orange, Randolph, and Stanly counties.

This is an Appalachian and Piedmont species, ranging from southwestern PA south to the FL Panhandle and northeastern MS.
AbundanceRare and somewhat local, declining to strongly declining in recent decades, for unknown reasons. Not nearly as numerous as one would expect from the range map, and likely absent now from some counties, at least in the Piedmont. This is a Watch List species.
HabitatThis species requires high pH soil, typically growing in rich soils such as Basic Mesic Forests or Rich Cove Forests. It also grows in more mesic to drier forests, but always where the soil is circumneutral.
PhenologyBlooms from late March to May, and fruits soon after flowering.
IdentificationThis is the only yellow-flowered violet with divided leaves, though only one of the two varieties (var. tripartita) has such leaves. It has a stem to about 8-9" tall, with the 3-7 leaves emerging from the upper part of the stem, usually near the same place. Unfortunately, this variety, with three linear segments, is quite rare in NC and limited to the southern mountains (records from Buncombe, Henderson, and Jackson only). The more widespread variety -- var. glaberrima -- has leaves triangular, with no divisions; however, the base of the leaves is rounded to cuneate, as opposed to base cordate to hastate in the more common V. hastata (and those leaves have light green blotches with dark green veins). The several flowers, at the top of the stem, are bright yellow, like others in the genus. To find this scarce species, spend time in rich cove forests or other rich forests in the Piedmont, where it is greatly outnumbered by V. eriocarpa (which has leaves scattered along the stem from many nodes), the primary yellow-flowered violet of these habitats.
Taxonomic CommentsAs mentioned above, there are two well known and defined varieties; the main one in NC is var. glaberrima, with undivided leaves; var. tripartita is limited to a few counties in the southern mountains.

General note on Viola: In 2009-10 B.A. Sorrie (website map editor) went through the whole collection at NCU, annotating all specimens against those verified by experts in the genus. The range maps in RAB (1968) have been changed accordingly. More recently, H. Ballard and students are in the process of revising all Southeastern Viola, and they will recognize more species than are listed on this website, which follows Weakley (2018).
Other Common Name(s)Threepart Yellow Violet
State RankS2? [S2]
Global RankG5
State StatusW7
US Status
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