Lolium rigidum

Gaudin
Common names: Stiff ryegrass
Synonyms: Lolium strictum
Treatment appears in FNA Volume 24. Treatment on page 456.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants annual. Culms to 70 cm. Blades to 17 cm long, 0.5-5(8) mm wide. Spikes 3-30 cm, with 2-20 spikelets; rachises 0.5-3.5 mm thick at the nodes, with the spikelets somewhat sunken in the rachises and partly concealed by the glumes. Spikelets 5-18 mm long, 1-3(7) mm wide, with 2-8(11) florets. Glumes 4-20(30) mm, usually from 3/4 as long as to slightly exceeding the distal florets, rather indurate; lemmas 3-8.5(10.5) mm long, 0.9-2 mm wide; paleas slightly shorter than to slightly longer than the lemmas, usually unawned, sometimes awned, awns to 10 mm; anthers 1.2-3.2 mm. Caryopses 2.7-5.5 mm long, 1-1.5 mm wide, 3 or more times longer than wide. 2n = 14.

Distribution

Tex., Man., Calif., La., Oreg., Miss., Ariz., Mo.

Discussion

Lolium rigidum is native to Europe, North Africa, and western Asia. It has been found as a weed of roadsides and waste places at scattered locations in the contiguous United States and Canada.

Lolium rigidum intergrades with L. perenne, L. multiflorum, and, occasionally, L. temulentum. Hybrids with L. multiflorum are called Lolium xhubbardii Jansen & Wacht. ex B.K. Simon.

Selected References

None.

Lower Taxa

None.