Allium cernuum Roth
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Bulb slenderly conic, very gradually tapering into the stem; lvs several, arising near together at the soil-surface, shorter than the stem, 2–4(–8) mm wide; scape 3–6 dm, abruptly declined near the top; umbel nodding (at least in bud), many-fld, without bulblets; pedicels 12–25 mm, becoming rigid; tep white to rose, ovate or elliptic, 4–6 mm, obtuse or subacute; stamens exsert; filaments barely widened at base; fr obovoid, 3-lobed, 4 mm, each valve (and each lobe of the ovary) bearing 2 erect triangular processes near the top; 2n=14. Dry woods, rocky banks, and prairies; N.Y. to Mich., Minn., and B.C., s. to Va., Ky., and Mo., and in the mts. to Ga., Ala., and Ariz. July, Aug. (A. allegheniense; A. oxyphilum Wherry, of shale-barrens, with few, whitish fls, may merit some recognition)