Monographs Details: Triadenum tubulosum (Walter) Gleason
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - Erect, rhizomatous perennial 6–10 dm, branched above; lvs thin, lacking translucent glands or superficial dots, oblong or elliptic-oblong to elliptic-oblanceolate, 7–13 × 2–5 cm, obtuse or rounded above, usually tapering to an acute to truncate base; cymes few-fld, on peduncles to 12 mm; sep at maturity narrowly oblong, acute, 4–6 mm; pet 5–7 mm; fr 9–11 mm; styles 1 mm. Wooded swamps on the coastal plain; se. Va. to La., n. in the interior to s. Mo. and s. O. July–Sept. (T. longifolium; Hypericum t.)