Species Profile - Poa trivialis

Poa trivialis L.

Common Name: Rough bluegrass

Synonyms and Other Names:

rough-stalked meadow-grass, rough meadow-grass

Identification: This grass is perennial, short-lived, somewhat loosely to densely tufted, usually weakly stoloniferous, with basal intra-vaginal branching .

Culms are 25-120 cm, decumbent to erect, sometimes trailing and rooting at the nodes, terete or weakly com-pressed; nodes are terete or slightly compressed, (0)1-3 exserted. Sheaths closed for about 1/3-1/2 their length, compressed, usually densely scabrous, bases of basal sheaths glabrous, distal sheath lengths 0.5-4 times blade lengths; collars smooth or scabrous, glabrous; ligules 3-10 mm, scabrous, acute to acuminate; blades 1-5 mm wide, flat, lax, soft, sparsely scabrous over the veins, margins scabrous, apices narrowly prow-shaped. Panicles 8-25 cm, erect or lax, pyramidal, open, with 35-100+ spikelets; nodes with 3-7 branches; branches 2-8(10) cm, ascending to spreading, flexuous to fairly straight, angled, angles densely scabrous, crowded, with 5-35 spikelets in the distal 1/2-3/4. Spikelets 2.3-3.5 mm, lengths to 3 times widths, laterally compressed; florets 2-4, bisexual; rachilla internodes smooth or muriculate. Glumes distinctly keeled, keels scabrous; lower glumes subulate to narrowly lanceolate, usually arched to sickle-shaped, 1-veined, distinctly shorter than the lowest lemmas; calluses webbed, hairs over 2/3 the lemma length; lemmas 2.3-3.5 mm, lanceolate, distinctly keeled, keels usually sparsely puberulent to 3/5 their length, marginal veins usually glabrous, infrequently the proximal 1/4 softly puberulent, intercostal regions smooth, glabrous, upper lemmas sometimes glabrous, lateral veins prominent, margins glabrous, apices acute; palea keels smooth, muriculate, tuberculate, or minutely scabrous; anthers 1.3-2 mm. 2n = 14.

Size: 25-120 cm

Native Range: Eurasia. Native to temperate and cold areas of the Northern Hemisphere, from the lowlands to alpine levels in the mountain areas.


This map only depicts Great Lakes introductions. Click here for Great Lakes region collection information

Great Lakes Nonindigenous Occurrences: Introduced into the great Lakes region in the early 1800s.It occurs in all Great Lakes states and is widespread throughout the region.

Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Poa trivialis are found here.

State/Province	First Observed	Last Observed	Total HUCs with observations†	HUCs with observations†
IN	1983	2012	2	Little Calumet-Galien; St. Joseph
MI	1843	2009	6	Clinton; Great Lakes Region; Huron; Manistee; Southeastern Lake Michigan; St. Clair-Detroit
MN	2008	2008	1	St. Louis
NY	1843	2008	11	Cattaraugus; Eastern Lake Erie; Great Lakes Region; Indian; Lake Ontario; Lower Genesee; Northeastern Lake Ontario; Oneida; Oswego; Seneca; Upper Genesee
OH	1999	1999	1	Ashtabula-Chagrin
PA	2008	2008	1	Lake Erie
WI	2008	2008	2	Northwestern Lake Michigan; Southwestern Lake Michigan

Table last updated 11/26/2024

† Populations may not be currently present.

Ecology: Poa trivialis can be found in meadows, open woodlands, prairies, and disturbed sites. Large climate range. This species tolerates shade, especially in old orchards. It is drought sensitive but tolerates a large range of soil humidity, though it prefers normally drained to cool soils. It also favors nutrient-rich soils (eutrophic species) and slightly acid to neutral pH. It has low requirements for soil texture. Poa trivialis can germinate in a wide range of temperatures, but those less than 50 degrees F delay germination. Precipitation optimum ranges from 20 to 50 inches annually. It can withstand temperatures to -28 degrees F, and requires 120 frost-free days (Gubanov et al 2003, USDA 2008).

Means of Introduction: Most likely brought by early settlers, and may have been introduced more recently in lawn seed.

Status: Introduced and naturalized.

Great Lakes Impacts:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Socioeconomic Beneficial

There is little or no evidence to support that Poa trivialis has significant environmental impacts in the Great Lakes.
Poa trivialis competes with native species, reducing overall diversity and total annual production of forage and altering species composition, but not to a particularly damaging degree in the Great Lakes region.

There is little or no evidence to support that Poa trivialis has significant socioeconomic impacts in the Great Lakes.
This species is managed as a nuisance in turfgrass (such as fairways and sports fields).

There is little or no evidence to support that Poa trivialis has significant beneficial impacts in the Great Lakes.
Poa trivialis is widely planted as a pasture grass. It is used for forage hay and pasturage in marshlands.

Management: Regulations (pertaining to the Great Lakes region)
There are no known regulations for this species.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Poa trivialis is used as a turf grass, often overseeded with Bermuda grass. Most research on management of this species focuses on promotion of the plants rather than control. Its tendency to yellow in the heat of summer makes it undesirable in some turf applications, and most information on control is based on these applications.

Biological
Combining herbicides with overseeding an alternative desired grass will help discourage the regrowth of surviving P. trivialis and improve overall success of control (Morton and Reicher, 2007).

Chemical
Non selective control with glyphosate (Roundup) followed by reseeding has been the only option for control. A herbicide called sulfosulfuron (Certainty®) is currently being labeled by Monsanto for selective control of Poa trivialis in creeping bentgrass (Street & Sherratt 2013).

Other
This species has low tolerance for high temperatures and drought.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

References (click for full reference list)

Other Resources:

USDA/NRCS PLANTS Database

Author: Cao, L., and R. Sturtevant

Contributing Agencies:

Revision Date: 8/9/2019

Citation for this information:
Cao, L., and R. Sturtevant, 2024, Poa trivialis L.: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/GreatLakes/FactSheet.aspx?Species_ID=2670, Revision Date: 8/9/2019, Access Date: 11/26/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.