Ruellia strepens L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stems 3–10 dm, minutely puberulent in narrow strips on 2 opposite sides; petioles 5–20 mm; main lvs thin, ovate or lance-ovate, 5–15 cm, acute or short-acuminate, abruptly narrowed or cuneate at base, glabrous or sparsely strigose; fls from a few nodes near the middle of the stem, 1–3, subtended by 2 ovate leafy bracts, on an axillary common peduncle 5–15 mm or terminal on a leafy axillary branch; cal-lobes lanceolate, 1–2 cm × 2–4 mm; cor 3.5–5 cm, the slender tube about equaling the throat; fr glabrous; 2n=34. Moist woods; N.J. to O. and Io., s. to S.C., Ala., and Tex. May– July. Cleistogamous forms with smaller fls in cymose clusters from several axils occur occasionally.