Lonicera xylosteum L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Much like no. 8 [Lonicera oblongifolia (Goldie) Hook.], but with hollow twigs, shorter (12–20 mm) peduncles, well developed bracts and bractlets, separate, glandular ovaries, and mostly shorter (7–12 mm) cor; 2n=18. Native of Europe, occasionally escaped and ± established in our range. May, June.