Vicia angustifolia 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. 1 [Vicia sativa L.]; lfls 3–5 pairs, linear to narrowly elliptic, seldom broader; stipules with or without a glandular spot beneath; fls 12–18 mm; cal-tube 4–6 mm, the lobes 3–6 mm; fr nearly black; 2n=12, 14. Native of Europe, established in fields, roadsides, and waste places throughout our range. Perhaps better treated as V. sativa var. angustifolia (L.) Ehrh.