Plants perennial; taproot stout; caudex much-branched, woody. Flowering stems erect, with 3-6 pairs of leaves below inflorescence, 30-80 cm, short-pubescent, glandular and somewhat viscid distally. Leaves: proximal petiolate, blade oblanceolate, 3-6(-8) cm × 5-15 mm (including petiole), base tapered into short petiole, apex acute to obtuse and apiculate, short-pubescent on both surfaces, pubescence rather sparse adaxially; cauline leaves sessile, blade elliptic-lanceolate, 2-6 cm × 5-15 mm. Inflorescences branched, several-many-flowered, open, bracteate, flowering portion to 15 cm and ca. 1/ 2 as broad, glandular and viscid; cymules usually 1-3-flowered; bracts narrowly lanceolate, shorter than pedicel; peduncle shorter than internodes. Pedicels divaricate, sharply bent distally, 5-15 mm. Flowers nodding; calyx prominently 10-veined, tubular to campanulate, umbilicate but narrowed at base, lobed, 9-11 × 3-5 mm in flower, in fruit ovate to turbinate, 5-8 mm broad, viscid-pubescent, veins parallel, green, papery between; lobes 5, narrowly lanceolate, obtuse, 2-3 mm, ciliate; corolla ± white, often greenish abaxially and pink tinged, 2 times calyx; petals 2-lobed, margins entire to erose, appendages linear, narrow, 1-2.5 mm; stamens often long-exserted; filaments pubescent at base; styles persistent, 3, long-exserted, filamentous, exceeding 2 times calyx. Capsules broadly ovoid, ca. equaling calyx, opening by 6 ascending, triangular teeth; carpophore 2-3 mm. Seeds reddish brown, reniform, 1.2-1.8 mm broad, coarsely papillate. 2n = 48.

Flowering summer. Coniferous forest openings and mixed woodlands, dry slopes; 500-2800 m; Calif., Oreg.

Silene bridgesii is similar to S. lemmonii but usually can be distinguished by its larger size, broader and larger leaves, the near-absence of sterile basal shoots, and larger floral parts and fruits. Although S. longistylis has often been cited as a synonym of S. lemmonii, examination of the holotype (Henderson s.n., GH) indicates that it is referable to S. bridgesii.

Silene bridgesii is found in the Sierra Nevada and southern Cascades.