J. Bot. Res. Inst. Texas 1: 166, figs. 3A,D, 9. 2007.
Annuals. Stems erect, simple, sometimes few-branched, (7–)9–21(–29) cm, glabrous or glabrate proximally, glandular-puberulent distally. Leaves: blade lanceolate-ovate to oblong, not falcate, 6–13(–18) × 1–3(–5) mm, margins entire or with 1 or 2(or 3) pairs of blunt teeth distally, apex obtuse, surfaces glabrate or glandular-puberulent. Pedicels slender, (5–)8–17(–22) mm, length 0.9–2(–2.3) times bract, sparsely to densely glandular-puberulent; bracteoles 2, 2–4.5 mm. Flowers: sepals distinct, lanceolate, 2–4.5 mm; corolla 7–9 mm, tube and limb white tinged with pink or purple, veins lavender or purple; style 1.9–2.2 mm. Capsules subglobular to ovoid, 2.5–3.6 × 2–3.7 mm. Seeds 0.3–0.5 mm.
Phenology: Flowering Apr–May.
Habitat: Seasonal pools on granite outcrops.
Elevation: 100–300 m.
Gratiola graniticola is known from about a dozen counties in the southeastern piedmont of northern Georgia and north-central South Carolina, where it occurs only on granite flatrocks (D. Estes and R. L. Small 2007; D. F. Brunton 2009).