Lolium rigidum
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.