New York Natural Heritage Program
Blue Wild Rye
Elymus glaucus ssp. glaucus
Monocots

General Description [-]
Blue Wild Rye is a perennial grass which grows in clumps 30 to 140 cm tall, occasionally spreading by underground stems (rhizomes). The leaf blades are 10 to 17 mm wide and usually without hairs. The erect stems are topped by a spike (inflorescence), 5 to 12 cm long and 5 to 15 mm wide. As in all grasses, the small, inconspicuous flowers occur in scaly structures called spikelets. Elymus glaucus ssp. glaucus usually has 2 spikelets per node and internodes 4 to 8 mm long. Each spikelet has 2 to 4 florets, each with awns projecting 10 to 25 mm from one of the scales (the lemma) (FNA 2008).

Best Life Stage for Proper Identification [-]
Fruiting individuals are needed for positive identification.

Similar Species [-]
Elymus glaucus is unique among the Elymus species of eastern North America for having glumes (the bracts at the base of each spikelet) with hyaline (thin and translucent), overlapping margins. In New York, it is most similar to E. riparius, E. villosus, and E. virginicus. In addition to having hyaline-edged glumes, it differs from these species by having fewer (6 to 7) stem leaves than do E. riparius (9 to10), or E. virginicus ( 7 to 10), and having longer (7.5 to 10.5 mm long) paleas than does E. villosus (5.5 to 6.7 mm long). Elymus glaucus ssp. glaucus is the only subspecies of E. glaucus which occurs in New York (FNA 2007, Voss 1972).
Blue Wild Rye Images
click to enlarge
The Best Time to See
The best time to see this plant is when it is fruiting, from mid-July through October.
J F M A M J J A S O N D
Fruiting
The time of year you would expect to find Blue Wild Rye fruiting (green shading) in New York.