Calyx 5–12-parted, the divisions slender. Corolla 5–12-parted, wheel-shaped. Stamens 5–12; anthers soon recurved. Style 2-cleft or -parted, slender.—Biennials or annuals, with slender stems, and cymose-panicled handsome (white or rose-purple) flowers, in summer. (Dedicated to L. Sabbati, an early Italian botanist.)
[*] Corolla 5-parted, or rarely 6–7-parted.
[+] Branches all opposite and stems more or less 4-angled; flowers cymose; calyx with long and slender lobes.
[++] Corolla white, often turning yellowish in drying.
1. S. paniculàta, Pursh. Stem brachiately much-branched (1–2° high); leaves linear or the lower oblong, obtuse, 1-nerved, nearly equalling the internodes; calyx-lobes much shorter than the corolla.—Low grounds, Va. to Fla.
2. S. lanceolàta, Torr. & Gray. Stem simple (2–3° high) bearing a flat-topped cyme; leaves ovate-lanceolate or ovate, 3-nerved, the upper acute, much shorter than the internodes; calyx-lobes longer and flowers larger than in n. 1.—Wet pine barrens, N. J. to Fla.
[++][++] Corolla rose-pink, rarely white, with a yellowish or greenish eye.
3. S. brachiàta, Ell. Stem slightly angled, simple below (1–2° high); leaves linear and linear-oblong, obtuse, or the upper acute; branches rather few-flowered, forming an oblong panicle; calyx-lobes nearly half shorter than the corolla.—Dry or low places, Ind. and N. C. to La. and Fla.
4. S. angulàris, Pursh. Stem somewhat 4-winged-angled, much branched above (1–2½° high), many-flowered; leaves ovate, acutish, 5-nerved, with a somewhat heart-shaped clasping base; calyx-lobes one third or half the length of the corolla.—Rich soil, N. Y. to Ont. and Mich., south to Fla. and La.
[+][+] Branches alternate (or the lower opposite in n. 5); peduncles 1-flowered.