Maltese-cross, scarlet lychnis, lychnide de Chalcédoine, croix de Jérusalem

Lychnis chalcedonica Linnaeus, Sp. Pl. 1: 436. 1753; Agrostemma chalcedonica (Linnaeus) Doellinger

Plants perennial, coarse, rhizomatous; rhizome branched, stout. Stems erect, few-branched, 50-100 cm, hispid. Leaves rounded into tightly sessile base; blade lanceolate to ovate, 5-12 cm × 20-60 mm, apex acute, sparsely scabrous-pubescent on both surfaces, scabrous-ciliate on abaxial margins and midrib; basal leaf blades broadly spatulate. Inflorescences subcapitate between terminal pair of leaves, 10-50-flowered, congested, bracteate; bracts lanceolate, herbaceous, ciliate. Flowers sessile to subsessile, 10-16 mm diam.; calyx 10-veined, narrow and tubular in flower, clavate in fruit, 12-17 mm, margins dentate, lobes triangular-lanceolate, 2.5-2.5 mm, coarsely hirsute; petals scarlet, sometimes white or pink, clawed, claw equaling calyx, limb spreading, obovate, deeply 2-lobed, 6-11 mm, shorter than calyx, appendages tubular, 2-3 mm; stamens equaling calyx; stigmas 5, equaling calyx. Capsules ovoid, 8-10 mm, opening by 5 teeth; carpophore 4-6 mm. Seeds dark reddish brown, reniform-rotund, 0.7-1 mm diam., coarsely papillate; papillae ca. as high as wide. 2n = 24 (Europe).

Flowering summer. Roadsides, waste places, open woodlands; 0-300 m; introduced; Alta., B.C., Man., N.B., N.S., Ont., P.E.I., Que., Sask.; Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Pa., Vt., Wis.; Europe.

Silene chalcedonica is widely cultivated but rarely escapes and probably does not persist.