Lolium rigidum Gaudin

Family: Poaceae, Tribe: Poeae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)

Lolium loliaceum (Bory & Chaubard) Hand.-Maz.

Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

rigid ryegrass

Primary Disseminule Type


Description (diagnostics are in brown)

Spikelets solitary, sessile, consisting of 2–8(11) fertile florets with similar-looking though diminished sterile florets at apex, oblong, laterally compressed, 5–18 mm long x 1–3(7) mm wide, disarticulating below each fertile floret at maturity.

Glumes usually 1, 2 in terminal spikelets, unawned. Lower glume absent from all but the terminal spikelet. Upper glume persistent, slightly shorter to slightly longer than spikelet, similar to fertile lemma in texture, lanceolate or narrowly oblong, 4–20(30) mm long, coriaceous, without keels, 3–7-veined, surface smooth or asperulous, glabrous, apex obtuse or acute.

Fertile florets: rachilla persistent, glabrous to pubescent, 0.9–2.8 mm long (0.25–0.5 length of lemma) when empty (no sterile floret attached), callus very short, blunt, glabrous.

Lemma oblong to lanceolate, 3.2–8.5(10.5) mm long x 0.9–2 mm wide, coriaceous, without keel, (3)5-veined, surface smooth or finely scaberulous, apex entire or irregularly notched, obtuse to acute, awnless or rarely awned to 3(10) mm long.

Palea slightly shorter to slightly longer than lemma, keels scaberulous.

Caryopsis elliptic to oblong, 2–5.5 mm long x 0.7–1.5 mm wide, typically 3+ times longer than wide, dark brown, hilum linear.

Similar Species

Similar Species Comparison Chart

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)