Monographs Details: Hypericum canadense L.
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 - Annual, or perennating by short, leafy stolons; stems slender, erect, 1–6 dm; lvs linear to narrowly oblanceolate, 1–4 cm × 1–4(–5) mm, obtuse, tapering to the narrow base, 1-nerved or weakly 3-nerved; infl compact to more often loose, usually with fewer fls than no. 21; bracts subulate; sep lanceolate, acute or acuminate, 3–5 mm; pet 2.5–3 mm; stamens 12–22; styles 3(4), under 1 mm; fr purple, mostly conic, 4–6 mm; seeds 0.5 mm; 2n=16. Sandy or muddy shores or wet meadows; Nf. and Que. to Minn., s. to Ga. and Ala., more common eastward. July–Sept. Hybridizes with several other spp.; one such apparent hybrid, approaching no. 21 [Hypericum mutilum L.] or 22 [Hypericum boreale (Britton) E. P. Bicknell], has been called H ×dissimulatum E. P. Bicknell.