Trisetum spicatum
Downy oat-grass
Image of Trisetum spicatum

Photo by Susan R. Crispin 

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Key Characteristics

Small tufted grass (50 cm) of bedrock habitats, with hairy upper leaf surfaces and sheaths; flowering panicle 3-10 cm long and dense, the spikelets mostly 2-flowered, the lemmas 2-toothed and at least the upper one awned.

Status and Rank

  • State Status: SC
  • State Rank: S2S3
  • Global Rank: G5

Occurrences

County NameNumber of OccurrencesYear Last Observed
Alger11973
Chippewa11985
Keweenaw272014
Marquette31996
Ontonagon11982
Distribution map for Trisetum spicatum

Updated 7/21/2017. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

Downy oat-grass occurs in rock crevices and on shores where it is found along the immediate shore, where it establishes in crevices, often well within the wave-splash zone. It occurs principally in association with calcareous substrates, but occasionally can be found on acid substrates of various igneous and metamorphic bedrocks.

Natural Community Types

Methodology

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Associated Plants

Northern white cedar, balsam fir, sand cherry, ground juniper, buffaloberry, Alpine bluegrass, bulrush sedge, Hill's thistle, and flattened spike-rush, little bluestem, prairie dropseed, cat's foot, Canadian milk vetch, harebell, sedges, Indian paintbrush, field chickweed, bastard toad flax, grass, hair grass, prairie smoke, bee-balm, shrubby cinquefoil, old field goldenrod.

Management

Primarily requires protection of the shoreline habitat and perpetuation of natural disturbance (winter ice, storms, wind) and hydrological regimes. This community occupies a stressed, potentially unstable environment; many of the species found in this community do not tolerate later stages of succession and require management that prevents woody plant encroachment. Protect from development and trampling from recreational activities.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Sep 20, 2017]

More Information

See MNFI Species Abstract

References

Survey References

Technical References

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