Sand Wildrye - Elymus flavescens
State Rank Reason (see State Rank above)
Sand wildrye occurs at the edge of its range in Montana, where it is known from one small population in the Centennial Valley sandhills. It requires early successional sandy habitats, which are localized in sand deposition areas of the dunes. This habitat is at risk from dune succession and stabilization that can result from suppression of natural disturbance regimes such as fire and grazing.
Stems solitary to few-bunched, 60–100 cm. Leaves: blades 3–6 mm wide, inrolled. Inflorescence 10–22 cm long, the rachis continuous and erect. Spikelets mostly 2 per node, 10–20 mm long; glumes narrow, faintly 3-nerved, tapering to an awn-tip. Lemmas mostly 2 to 5 per spikelet, copiously long-hairy, awnless or awn-tipped (Lavin in Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX
Fruiting occurs in July-August.
The long-hairy, almost feathery appearance of the spikelets separates this species from other members of Elymus and Agropyron (sensu lato). Elymus innovatus is also rhizomatous with hairy lemmas, but the hairs are not nearly as long, and the spikes are usually less than 10 cm in length.
WA and OR, east to southern ID and southwest MT. Peripheral.
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Sand wildrye occurs in sandy soils throughout its range. In Montana it is found in sand-deposition areas of sand dunes, where it is associated with Stipa comata and Agropyron caninum. The species has also been found on sandy roadsides.
Ecological Systems Associated with this Species
Historically, the early successional, open-sand habitat required by this species was maintained by a fire cycle of 20-30 years and ungulate grazing. Pocket gopher (Thomomys talpoides) activity also appears to be an important force in initiating blowouts and maintaining early seral vegetation (Lesica and Cooper 1998).
Plant succession in open sand areas leads to a reduction in the open-sand habitat this plant requires (Lesica and Cooper 1998). Its early successional habitat could likely be maintained with restoration of the historic fire regime and moderate grazing, at least in years following burns. Compaction and severe disturbance by off-road vehicle use may also damage its habitat.
Threats or Limiting Factors
STATE THREAT SCORE REASON
Reported threats to Montana's populations of Sand Wildrye concern management actions that lead to habitat loss (MTNHP Threat Assessment 2021). Sand dune substrates that are occasionally impacted by fire and wind erosion are critical to population survival. Fire suppression and vegetation management intended to stabilize sand dunes reduces available area for Sand Wildrye to colonize. Information on the scope, severity, and timing of this threat is needed.
- Literature Cited AboveLegend: View Online Publication
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Additional ReferencesLegend: View Online Publication
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- Culver, D.R. 1994. Floristic analysis of the Centennial Region, Montana. M.Sc. Thesis. Montana State University, Bozeman. 199 pp.
- Lesica, P. & S. V. Cooper. 1998. Succession and disturbance in sandhills vegetation: constructing models for managing biological diversity. Conservation Biology 13:293-302.