Erect, branching, glandular-hairy annual 1-3 dm; lvs linear, 1-2 cm, obtuse, narrowed below but scarcely petiolate; pedicels 10-15 mm, arising from many or most axils; sep linear-spatulate, unequal, 3 mm; cor 5-6 mm, blue-purple, with yellow on the palate, the spur 1.5-2 mm; fr subglobose, 5 mm; 2n=14, 28. Native of Europe, now widely established in waste places, especially on cinder railway-ballast, throughout our range. June-Sept. (Linaria m.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.