Linaria vulgaris Miller, Gard. Dict. ed. 8: no. 1 (1768).
Perennial, green or glaucescent, glabrous below, sometimes glandular-pubescent in inflorescence, reproducing vegetatively by adventitious buds; fertile stems numerous or rarely solitary, 25-120 cm, erect or ascending, simple or branched; sterile stems usually absent. Leaves 20-60 x 1-5 (-15) mm, the length (3-) 10-35 x breadth, linear, narrowly elliptic or linear-oblanceolate, acute, flat, attenuate, with 1 (-3) main veins, alternate or with a single whorl of 3 at base. Inflorescence with 5-30 (-50) flowers, more or less dense in flower and fruit. Bracts 3-25 mm, linear to lanceolate, acute, leaf-like below. Pedicels 2-8 (-13) mm in flower and fruit, erect. Calyx-lobes more or less equal, 3-6 x 1-2 (-2.5) mm, lanceolate to ovate, acute or acuminate, the margins not scarious. Corolla (19-) 25-33 mm, pale to bright yellow, usually with orange palate, glabrous externally; tube 6-10 mm broad at mouth; adaxial lip sinus 2.2-4.5mm; abaxial lip sinus 3-3.5 mm; spur 10-15 mm, 2-3 mm broad at base, more or less straight, shorter than rest of corolla. Capsule 5-11 mm, ovoid or oblong-globose, glabrous. Seeds 1.8-3 mm, oblong-orbicular to suborbicular, black; wing 0.4-0.7 mm broad; disc tuberculate; tubercles usually isodiametric, hemispherical to conical, rounded to subacute, rarely narrowly conical or forming short ridges. Modified from Sutton (1988).
2n = 12 (Heitz, 1926: 644; 1927a: 51; East, 1933: 327; Valdés, 1969: 244; Fernandes, Queirós and Santos, 1977: 50; Van Loon & Van Setten, 1982: 592).
Europe except for extreme N and much of S to C Asia, naturalized widely in temperate regions. Al An Au Be Br Bu Ch(Ga Ha Js Sa Sd Xn) Co Cz Da Fe Ga Ge Gr Hb He Ho Hs Hu It Ju No Po Rm Rs Su Tu [Ce Cn Us].
Type: [BRITAIN]: sine leg. herb. Miller (syn. BM!).