Bulbous bluegrass (Poa bulbosa)

Common Names: Bulbous meadowgrass

Description: Introduced from Europe as a forage grass to the Pacific Northwest.

Habit: Tuft- or sod-forming grass sometimes decribed as a perennial, an annual and an annual with "perennial tendencies".

Leaves: Mostly basal or on lower stem, up to 4 in. long, 1-2.5 mm wide, hairless, folded or flat, and boat-shaped at the tip. Sheaths hairless with fused edges. Ligule is 2-4 mm long, blunt to pointed at the tip with smooth nodes.

Stems: Erect or spreading from the base and rising at a lower node. Unbranched, hairless, clump-forming. Base is thickened, forming a bulb.

Flowers: Open to compact branching cluster, 6 in. long, branches spreading to ascending to erect. Spikelets are single at the tips of short branchlets, green to purple in color, 2-7 florets that are elongated bulbets, up to 20 mm long.

Fruit and seeds: Bulblets turn dark purplish at the base and greee to purple on the elongated tip. Shed individually. Seeds seldom produced. Bulblets can take root immediately.

Habitat: Native to Europe. Can be found growing in roadsides, fields, open woods, lawns, waste areas and other disturbed areas.

Reproduction: Reproduces from bulblets which sprout from the parent plant and from basal bulbs.

Similar species: Native onion species (Allium spp.)

Monitoring and rapid response: Hand-pulling can be effective but is difficult to remove all bulbs. Mowing is now considered to be effective but can be controlled with early season cultivation or tillage. Can be effectively controlled using any of several readily available general use herbicides such as glyphosate and imazapyr.

Credits: The information provided in this factsheet was gathered from Minnesota Wildflowers, UC Davis Weed Research & Information Center, Utah State University Extension and the U.S. Department of Agriculture, Forest Service.

Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org).Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).

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