Plants perennial; taproot stout, branched; caudex compact, multicapitate. Stems erect, simple proximal to inflorescence, 30-90 cm, glabrous, viscid, especially at nodes. Leaves: basal numer-ous, tufted, petiolate, blade ob-lanceolate to linear-oblanceo-late, 4-15 cm × 2-10 mm (in-cluding petiole), apex acute, glabrous, ciliate at base; cauline in 2-4 pairs, connate proximally, sessile. reduced distally, blade linear-lanceolate, 2-10 cm × 2-8 mm, apex acute, glabrous, ciliate at base. Inflorescences paniculate, consisting of short, interrupted cymes, narrow, bracteate, bracteolate; cyme 3-10-flowered, proximal ones pedunculate; peduncle to 3 cm; bracts leaflike, to 3 cm; bracteoles broadly lanceolate, 3-10 mm, margins membranous, apex acuminate. Pedicels shorter than calyx, glabrous but viscid. Flowers 14-22 mm diam.; calyx purple, obscurely veined, narrowly campanulate in flower, 6-10 × 3-4 mm, clavate in fruit, 10-15 × ca. 5 mm, papery, puberulent, lobes ovate, ca. 1.5 cm, margins narrow, membranous, apex obtuse; corolla purple or dark pink (rarely white), ca. 1 2-2 times calyx, clawed, claw equaling calyx, limb spreading, obovate, entire or slightly notched, 5-9 mm, appendages 2, oblong, 3 mm; stamens shortly exserted; stigmas 5, shortly exserted. Capsules ovoid, equaling calyx, opening by 5 teeth; carpophore 3-5 mm. Seeds dark brown, reniform, 0.3-0.5 mm, finely tuberculate. 2n = 24 (Europe).

Flowering early summer. Roadsides, waste ground, fields; 0-500 m; introduced; Conn., Maine, Mass., N.H., N.Y., Ohio; Europe.

Subspecies viscaria is an attractive garden plant similar to S. suecica but somewhat larger and sturdier with viscid pedicels. It occasionally escapes but does not persist.