Leafy Bentgrass - Agrostis pallens
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Agrostis pallens has been found in scattered locations within western Montana. There are fewer than 10 collections in the State Herbaria (University of Montana and Montana State University), and where it is present indications of rarity have not been noted. Most herbaria collections were made in and after 1980. This grass may be under-collected because it can easily be mis-identified as another species of Agrostis. Current data on locations, population sizes, habitat, and threats are needed.
- Details on Status Ranking and Review
ScoreF - 20,000-200,000 sq km (~8,000-80,000 sq mi)
Comment31,466 square kilometers
Area of Occupancy
ScoreD - 6-25 4-km2 grid cells
CommentPlant occurs in 7 of the 30,590 4x4 square-kilometer grid cells that cover Montana.
Number of Populations
ScoreB - 6 - 20
Number of Occurrences or Percent Area with Good Viability / Ecological Integrity
ScoreB - Very few (1-3) occurrences with excellent or good viability or ecological integrity
Comment3 occurrences described as 'common' or 'moderately abundant' and assumed to be of good viability.
ScoreC - Moderate. Generalist or community with some key requirements scarce
CommentIn Montana Agrostis pallens grows in moist to wet meadows.
ScoreD - Low
PLANTS: A perennial, rhizomatous (creeping) grass. Stems 60-80 cm tall with most leaves arising from the stems.
LEAVES: Leafy, and generally attached from the lower half of the stem when in flower. Blades are 1.5-11.5 cm long and 2-6 mm wide. When young blades are flat but often become involute (rolled) with age. Ligules 1-6 mm long with the upper margin slightly cut (lacerate), or with irregular notches (erose).
INFLORESCENCE: A contracted to somewhat open panicle with many small flowers, 7–11 cm long. At anthesis (anther dehiscence) the panicle branches spread and ascend. Each node has several primary branches, which branch again along their entire lengths into many small secondary branches.
Spikelets are 3–3.5 mm long, green, yellow-green, or yellow with purple tinges which may make it appear darkish. Glumes are (sub-)equal 2-3.5 mm long, 1(-3) veined, with acute tips. Lemmas are (1.5-)2.2–2.5 mm long, awnless or with an apiculate awn, and with 5 veins which are at least prominent on the upper (distal) portions. Paleas are lacking or minute (to 0.2 mm).
The genus Agrostis comes from the Greek word, agros meaning ‘pasture’ or ‘green fodder’.
Sources: Harvey in FNA 2007; Lesica et al. 2012; and Giblin et al. [eds.] 2018.
Leafy Bentgrass grows from British Columbia south into Baja California, Mexico and east to western Montana and Utah (Harvey in FNA 2007).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
- Literature Cited AboveLegend: View Online Publication
- Flora of North America Editorial Committee. 2007. Flora of North America North of Mexico. Vol. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Oxford Univ. Press, New York. xxviii + 911 pp.
- Giblin, David E., Ben S. Legler, Peter F. Zika, and Richard G. Olmstead (editors). 2018. Flora of the Pacific Northwest: An Illustrated Manual. Second Edition. University of Washington Press in Association with Burke Museum of Natural History and Culture, Seattle, Washington. 882 pp.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Amme, David. No Date. California Agrostis (Bentgrass).
- Del Moral, Roger, and David M. Wood. 1988. Dynamics of Herbaceous Vegetation Recovery on Mount St. Helens,Washington, USA, after a Volcanic Eruption. Vegetatio, Vol. 74. No. 1, pp. 11-27.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.