Page authors: Don Knoke, David Giblin
Lolium multiflorum
annual ryegrass, Italian ryegrass, perennial ryegrass
Specimens
Photos

Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast.

Habitat: Roadsides and waste ground.

Flowers: May-July

Origin: Introduced from Europe

Growth Duration: Biennial, Perennial

Conservation Status: Not of concern

Pollination: Wind

Description:
General:

Glabrous biennial or short-lived perennial, the hollow culms 5-12 dm. tall.

Leaves:

Sheaths open; auricles well-developed on most of the leaves, up to 1.5 mm. long; ligules 0.5-1.5 mm. long, membranous; blades 4-8 mm. broad, flat or slightly involute.

Flowers:

Inflorescence a single terminal spike 10-25 cm. long, the spikelets on opposite sides of the continuous rachis to which they are attached edgewise; spikelets 8- to 15-flowered, up to 2.5 cm. long; glume acute, 7-12 mm. long, the glume next to the rachis lacking except on the terminal floret; lemmas slightly bifid, 5-nerved, usually with a sub-terminal dorsal awn 2-8 mm. long; paleas subequal to the lemmas, firm, 2-nerved.

Accepted Name:
Lolium multiflorum Lam.
Publication: Fl. Franç. 3: 621. 1779.

Synonyms & Misapplications:
Lolium multiflorum Lam. ssp. italicum (A. Braun) Schinz & R. Keller
Lolium multiflorum Lam. var. diminutum Mutel
Lolium multiflorum Lam. var. muticum DC.
Lolium perenne L. ssp. italicum (A. Braun) Husnot
Lolium perenne L. ssp. multiflorum (Lam.) Husn.
Lolium perenne L. var. aristatum Willd.
Lolium perenne L. var. multiflorum (Lam.) Parnell
Additional Resources:

PNW Herbaria: Specimen records of Lolium multiflorum in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Lolium multiflorum checklist entry

OregonFlora: Lolium multiflorum information

E-Flora BC: Lolium multiflorum atlas page

CalPhotos: Lolium multiflorum photos

17 photographs:
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