Brathydium ambiguum (Elliott) K. Koch; Hypericum ambiguum Elliott; H. axillare Lamarck; H. galioides var. ambiguum (Elliott) Chapman; H. galioides var. axillare (Lamarck) Grisebach; H. michauxii Poiret; Myriandra galioides (Lamarck) Spach; M. michauxii (Poiret) Spach

Shrubs, erect, forming rounded clumps, 5–15 dm. Stems: internodes 6-lined at first, soon 4-lined, then terete. Leaf blades narrowly oblong-elliptic or oblanceolate to linear, 15–32(–37) × 1–7 mm, base articulated, attenuate, margins recurved to revolute, apex rounded to acute, midrib obscurely branched. Inflorescences <narrowly cylindric>, 3–15-flowered <from apical node>, with (1–)3–5-flowered dichasia from 3–4 proximal nodes, sometimes with additional flowering branches. Flowers 9–14 mm diam.; sepals deciduous, not enclosing capsule, 5, oblanceolate-spatulate to linear, subequal or equal, 3.5–6.5 × 0.5–1.5 mm; petals 5, bright yellow, obovate-oblanceolate, 5–9 mm; stamens deciduous, 60–120; ovary 3-merous, <placentation parietal>. Capsules narrowly ovoid-conic, 4.5–6 × 2.5–3.5 mm. Seeds narrowly carinate, 0.7–0.8 mm; testa finely reticulate. 2n = 18.

Flowering summer (Jun–Aug). Wet or moist, open habitats (stream banks, flood plains, roadside ditches, low pine forest, etc.), coastal plain; 0–200 m; Ala., Fla., Ga., La., Miss., N.C., S.C., Tex.

The leaves of Hypericum galioides vary considerably in width; the lamina is always visible on either side of the midrib.