Linaria macroura (Bieb.) Bieb., Cent. Pl. 1 tab. 27 (1810).
Somewhat glaucous perennial, propagating vegetatively by root-buds, glabrous except for glandular-pilose to subglabrous inflorescence; fertile stems solitary or few, 30-50 (-90) cm, erect, stout, simple or rarely branched above, densely leafy except for 2.5-6 cm below inflorescence and sparsely leafy base; sterile stems not seen. Leaves 25-55 x 1.5-2 mm, the length (15-) 25-50 x breadth, linear-lanceolate or linear, acute, flat, attenuate, 1-veined, somewhat fleshy, mostly alternate. Inflorescence with (2-) 5-30 flowers, dense in flower, somewhat lax in fruit. Bracts 4-8 mm, narrowly deltate to linear-lanceolate, acute, sharply reflexed parallel to axis. Pedicels 1-2.5 mm, erect. Calyx-lobes subequal or conspicuously unequal, oblong-ovate or oblong, obtuse or truncate, glandular-pilose or glandular-ciliate, white-scarious; adaxial lobe 7-10 x 1.2-2 mm; lateral lobes 5-7 x 1.44 mm. Corolla 28-37 mm, bright yellow, often with violet veins, the throat with orange markings, sparsely glandular-puberulent externally; tube 7-10 mm broad at mouth; adaxial lip sinus 2-3 mm; abaxial lip sinus 1.8-3 mm; spur (10-) 12-17 mm, 2-4 mm broad at base, narrowly conical, straight, continuing line of tube, somewhat shorter than to more or less equalling rest of corolla. Capsule 9-14 mm, ovoid to oblong-ovoid, glabrous. Seeds 1.7-2.5 (-3.5) mm, orbicular or reniform-orbicular, blackish-brown; disc smooth. Modified from Sutton (1988).
2n = 12 (Heitz, 1926)
SE European Russia (Moldavia & Ukraine). Rs(Ee Ek Ew?).
Type: USSR: "in Tauriae et deserti caucasico-caspici apricis siccis, praesertim sabulosis, v-vi" Bieberstein? (not located).