Stems usually 3-10 together, 2.5-5 mm thick at base; nodes below the umbel (25-)35-60(-75); infl neither conspicuously leafy nor separated into distinct groups of involucres; involucres mostly 6-8+ mm wide across the appendages; the more widespread and n. phase, extending s. throughout Va. and to w. N.C., n. Ga., Ala., and Tex.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.