Shrub to 2 m; twigs solid; lvs oblong to oblanceolate, 3-7 cm, obtuse or acute at both ends, downy beneath, puberulent above when young; peduncles axillary, 2-4 cm; bracts and bractlets minute or none; ovaries glabrous, partly or wholly connate; cor yellow, 10-15 mm, hairy, strongly bilabiate, the tube 2.5-5 mm, the upper lip 4-lobed one fourth its length; style (and often filaments) hirsute; fr red. Swamps and bogs; N.B. to Man. s. to Pa., O., Mich., and Minn. May, June. (Xylosteon o.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.