Plants perennial; taproot stout, fleshy. Stems several, erect, simple proximal to inflorescence, 50-160 cm, glabrous to sparsely retrorse-puberulent proximally, more densely so and glandular distally. Leaves withered towards base at anthesis, in 10-20 pairs, sessile, gradually reduced distally; blade 3-veined, lanceolate to ovate, rounded into base, 4-12 cm × 20-50 mm, apex acute, not acuminate, glabrous to scabrous-puberulent adaxially, scabrous-puberulent abaxially. Inflorescences terminal, cymose, compound, many-flowered, bracteate, pedunculate, 15-25(-30) × 5-10 cm; bracts lanceolate, 3-30 mm; peduncle ascending. Pedicels 1-4 times longer than calyx, stipitate-glandular, puberulent. Flowers: calyx prominently 10-veined, tubular in flower, 18-25 × 3-4 mm, swelling in middle to 6-9 mm in fruit, umbilicate, constricted near base around carpophore, glandular-pubescent, especially on veins, veins green, lobes 2-4 mm, midrib lanceolate, margins often red tinged, broad, membranous; corolla scarlet, clawed, claw equaling calyx, limb oblong to elliptic, unlobed, rarely emarginate or shallowly 2-lobed, 10-20 × 5-6 mm, apex rounded, appendages 2, tubular, 2-4 mm; stamens exserted; styles 3(-5), exserted. Capsules ovoid-ellipsoid, narrowed at both ends, equaling calyx, opening by 6 (or 8 or 10) ascending teeth; carpophore 3-5 mm. Seeds dark reddish brown, reniform, 1.5-2 mm, with smooth and glossy, flat or concave sides, margins angled, shallowly rugose. 2n = 48. Flowering summer-fall. Dry prairies, rocky open woods, woodland edges and thickets; 100-400 m; Ala., Ark., Ga., Ill., Ind., Kans., Ky., Mo., Ohio, Tenn. Silene regia is a very distinct, spectacular species with tall stems, a narrow, many-flowered inflorescence, and bright red petals. It is probably related to S. laciniata via S. subciliata.

Silene regia is in the Center for Plant Conservation's National Collection of Endangered Plants.