Verbascum thapsus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stout, erect, 1–2 m, usually densely gray-tomentose throughout; lvs entire or shallowly crenate, the lower oblong or oblanceolate, to 3 dm, petioled, the upper progressively reduced, sessile, decurrent along the stem to the next lf below; spike-like infl very dense, 2–5 dm × 3 cm, usually solitary; cor yellow, 1–2.5 cm wide; upper 3 filaments short, densely white-villous, with short anthers; lower 2 filaments much longer, glabrous or nearly so, with linear anthers; stigma capitate; 2n=32, 36. Native of Europe, now abundant throughout most of temperate N. Amer., especially in disturbed sites. June–Sept. A hybrid with no. 4 [Verbascum phlomoides L.] is V. ×kerneri Fritsch.