Stately rose-gentian, Buckley’s sabatia

Herbs annual. Stems 4-angled, sometimes with wings to 0.2 mm wide, 0.6–3 dm, branching all or mostly alternate. Leaves basal and cauline present at flowering time; blade lanceolate to ovate, that is, widest proximal to middle, 0.8–2.5 cm × 3–13 mm. Inflorescences open cymes; pedicels 20–70 mm. Flowers 5-merous; calyx tube cam­panulate, 2–8 mm, commissural veins more prominent than midveins, strongly ridged, lobes linear, (4–)8–22 mm; corolla purplish pink, eye greenish yellow, pro­jections of eye into corolla lobes with a red border alternating with shorter white or paler yellow zones, tube 3–8 mm, lobes elliptic-rhombic, that is, widest near middle, 9–20 × 4–19 mm, apex ± acute; anthers coiling circinately.

Flowering early–mid spring. Prairies, fields, beaches, roadsides; 0–600 m; La., Okla., Tex.

Sabatia formosa closely resembles S. campestris, within which it often has been included. By its earlier flower­ing, however, S. formosa is to some degree repro­ductively isolated from S. campestris where the two species are sympatric. N. B. Bell and L. J. Lester (1980) provided molecular as well as morphological evidence supporting the recognition of S. formosa as a species, and further morphological support has been found in studies for this flora. In S. formosa, the largest leaves are generally at and near the base of the stem, with the basal rosette usually persisting at flowering time. In S. campestris, the proximal leaves are generally smaller than those at mid stem, and the basal rosette is absent. The corollas of S. formosa are more deeply pigmented than those of S. campestris. The corolla lobes of S. formosa tend to be elliptic-rhombic, widest near the middle, whereas those of S. campestris are obovate, widest distally.