Lindernia dubia (L.) Pennell
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Low, branching, glabrous or glandular annual 0.5–2(–3) dm; lvs entire or obscurely few-toothed; sep narrow, 3-nerved, 3–4.5 mm; cor 5–10 mm; later fls often cleistogamous; 2n=18, 32. Wet sandy or muddy shores; Que. and N.H. to N.D., s. to Fla. and Tex., and in the Pacific states. July–Sept. Two rather poorly defined vars., both widespread in our range. Var. dubia: Lvs to 3 cm, at least the lower ones narrowed to the base; pedicels relatively short, mostly 0.5–1.5 cm, surpassed by or only slightly surpassing their subtending lvs; seeds mostly 2–3 times as long as wide. (Ilysanthes d.; I. attenuata) Var. anagallidea (Michx.) Cooperr.: Lvs mostly 6–15 × 3–10 mm, all broadly rounded at base, or the lowermost ones a little narrowed; pedicels mostly 1–2.5 cm, all except sometimes the lowermost ones conspicuously surpassing the subtending lvs; seeds 1.5–2 times as long as wide. (L. anagallidea; Ilysanthes a.; I. inaequalis)