Culms 20-190 cm; nodes 4-9. Ligules 2-8 mm; blades to
28 cm long, 1-20 mm wide. Panicles 3-46 cm; branches usually
spreading, sometimes ascending. Spikelets (2)2.5-4(5.5) mm; rachilla
prolongations 0.1-1.3 mm, sometimes absent. Lower glumes (1.8)2.5-4(4.7)
mm, 1-veined; upper glumes (1.9)2.5-4(5) mm, 1(3)-veined; stipes 0.1-0.45
mm; lemmas 1.8-3.8 mm, 3(5)-veined, awns 0.1-2.5 mm or absent; paleas 2-veined,
with the veins very close together, or 1-veined; anthers 1, 0.4-1
mm. Caryopses 1.8-2.8 mm. 2n = 28.
Cinna latifolia is a circumboreal species, extending from Norway to the Kamchatka peninsula in Russia, and from Alaska to Newfoundland. It grows in moist to wet soil in open coniferous or mixed forests, swamps, thickets, bogs, and streamsides, at 0-2600 m. It flowers in late summer and fall. Cinna latifolia differs from C. arundinacea in its 1 (rarely 3)-veined upper glumes and its smaller spikelets. A collection from the Aleutian Islands had abnormally large (to 5.5 mm) and often 2-flowered spikelets (Brandenburg et al. 1991). Cinna latifolia is a variable species for which varietal names have been proposed; because the variation is continuous, no varieties are recognized in this treatment.
Much like no. 1 [Cinna arundinacea L.]; nodes usually 3-7; lvs to 15 mm wide; ligules colorless or nearly so; infl lax and open, with slender, divaricate or recurved branches, pale green and somewhat shining; first glume 2.3-3.8 (avg 3) mm; second glume 1-veined, 2.6-4.1 (avg 3.3) mm, nearly glabrous except on the keel, the scarious margins constituting half the total width; awn to 1.5 mm; 2n=28. Moist woods; circumboreal, s. to Pa., n. Ill., Minn., and Calif., and in the mts. to N.C.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.