Plants annual or biennial. Culms (35)50-120(300) cm. Blades (3)4-12 mm wide, usually glabrous. Spikes (2)4.5-12(19) cm, often nodding when mature; disarticulation in the rachis, at the nodes, tardy or the spikes not disarticulating. Glumes 8-20 mm, with scabrous keels, keels terminating in awns, awns 1-3 mm; lemmas 14-18 mm, smooth to scabridulous, awns 7-50 mm; anthers about 7 mm. 2n = 14, 21, 28.
Secale cereale is one of the world's most important cereal grasses;
it is also widely used in North America for soil stabilization and, particularly
in Canada, for whisky. When dry, the spike is often distinctly nodding.
Frederiksen and Petersen (1998) placed cultivated plants with a nondisarticulating rachis into Secale cereale L. subsp. cereale, and wild or weedy plants with a more fragile rachis into Secale cereale subsp. ancestrale Zhuk.
Robust annual (biennial) 6-12 dm, branched from the base; lvs flat, 3-7(-10) mm wide; spikes stout, 6-15 cm, arcuate-nodding; spikelets disarticulating above the glumes and between the florets; glumes equal, 7.5-15 mm, the strong keel scabrociliate; lemmas 12-16 mm, pectinate-ciliate on the keel and margins, with awn 2-7 cm; anthers ca 8 mm; 2n=14, 16, 27-29. European cultigen, often spontaneous in disturbed sites with us, but probably never persistent.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.