Stems 3-8 dm, villous with spreading hairs, or minutely recurved-hairy, or both; lvs lanceolate to ovate, the upper rather crowded, the main ones 4-12 cm, distinctly petioled, villous to subglabrous; cor 2.5-5 cm, the tube somewhat longer than to twice as long as the throat; fr glabrous or occasionally hairy; 2n=34. Moist or dry woods; N.J. to s. O. and s. Ind., s. to Fla. and Tex. (R. parviflora) Highly variable.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
This species prefers a dry, sandy soil and is found mostly in open places along roadsides and railroads, on dry, open wooded slopes, and in prairie habitats.
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Indiana Coefficient of Conservatism: C = 6
Wetland Indicator Status: N/A
Diagnostic Traits: perennial, usually unbranched; leaves opposite, petiolate; flowers sessile in axils of upper 1-3 nodes; calyx lobes linear-setaceous, <1.2 mm wide; corollas with 5, +/- equal lobes; stamens 4.