25. Silene involucrata (Chamisso & Schlechtendal) Bocquet, Candollea. 22: 22. 1967.
Lychnis apetala Linnaeus var. involucrata Chamisso & Schlechtendal, Linnaea 1: 43. 1826; L. gillettii B. Boivin
Plants perennial, sometimes with dense tufts of basal rosettes of leaves, subglabrous to pubescent and glandular; taproot slender or stout. Flowering stems several, erect, simple or branched, 10-45 cm, usually with 2-5 pairs of leaves. Leaves mainly basal, petiolate; blade narrowly oblanceolate, ± spatulate, 20-60 × 3-5(-10) mm (including petiole), glabrous to pubescent, especially on margins and abaxial veins, pubescence spreading, short, stiff, mainly eglandular. Inflorescences 1-3-flowered, open, bracteate, pubescent, usually densely so, hairs long, flexuous, purple-septate, mostly glandular; bracts narrowly lanceolate, 4-10 mm, usually pubescent. Pedicels usually several times longer than calyx. Flowers pedicellate, rarely sessile, erect, 8-16 mm diam.; calyx prominently 10-veined, not inflated or thin, campanulate or ovate, 8-20 mm, pubescent, especially on veins, rarely almost glabrous, hairs long and short purple-septate, ± glandular, veins heavily suffused with purple (rarely green), sinuses between veins pale, cream colored; petals white, often pink or purple tinged, claw equaling calyx, limb not differentiated from claw, emarginate to obovate, often 2-lobed, ca. 1/ 2 as long as calyx; stamens included in calyx, spreading horizontally; styles 5, included in calyx. Capsules equaling calyx, opening by 5 teeth, tardily splitting into 10. Seeds brown, winged, ± reniform to angular, 1-1.5 mm diam.; wing to 2 seed diam.
Subspecies 2 (2 in the flora): Greenland, nw Canada, Alaska, arctic Europe, e Asia (Russian Far East, Siberia).
Silene involucrata is a very variable circumpolar and arctic-alpine species complex. Many of the variants have been treated as species by earlier workers. Here, a single species with two subspecies is recognized.