Linaria canadensis (L.) Dum.Cours.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Slender annual or winter-annual from a short taproot, 1–5 dm, essentially glabrous throughout, producing a rosette of short, prostrate stems with assurgent tips, the lvs of which are mostly opposite or ternate and broader than those of the 1–several erect main stems, these with linear lvs 1–3.5 cm × 1–2.5 mm, all but sometimes the lowermost alternate; racemes nearly naked; cor rather light blue, the lower lip bearing 2 short white ridges that form a weakly developed palate barely closing the throat; fr 2–4 mm; seeds prismatic-angled; 2n=12. Mostly in sandy soil; Mass. and even Que. to Minn., s. to Fla. and Mex., and on the Pacific coast. Apr.–June. The common form in our range is var. canadensis, with the cor mostly 8–10 mm (exclusive of the 2–6 mm spur) and the seeds smooth or nearly so. The well marked var. texana (Scheele) Pennell, with larger fls (10–12 mm exclusive of the 5–9 mm spur) and densely tuberculate seeds, is more southern, barely reaching our range.