Plants annual or perennial (short‑lived), with
rhizomes but sometimes with short stolons, forming tufts or small clumps.
Flowering stems 30–120 cm long, erect (sometimes spreading at the very base),
glabrous or roughened toward the tip. Leaf sheaths open nearly to the base, the
ligule relatively short, truncate or broadly rounded. Leaf blades flat, usually
with a small pair of short auricles at the base (sometimes worn off or folded
inward in older materials), glabrous or more commonly roughened on the upper
surface. Inflorescences spikes, the spikelets alternate and not or only
slightly overlapping along 2 sides of the somewhat zigzag, persistent axis,
positioned with an edge against a shallow depression of the axis, all similar
in size and appearance and with fertile florets. Spikelets lanceolate to oblong‑elliptic
in outline, flattened, with 4–22 florets. Lower glume absent, except in the
terminal spikelet (where similar in shape to the upper glume, but shorter).
Upper glume often longer than the lowermost lemmas, shorter than to somewhat
longer than the rest of the spikelet, oblong‑lanceolate, pointed or
rounded at the tip, awnless, glabrous, strongly 3–11‑nerved. Lemmas
pointed or rounded at the tip, sometimes awned (with the awn attached slightly
behind the lemma tip), rounded on the back, 3–7‑nerved with the nerves
converging (arched inward) toward the tip, glabrous or somewhat roughened.
Paleas slightly shorter than to slightly longer than the lemmas, narrowly
elliptic. Stamens 3, the anthers yellow. Fruits somewhat flattened, with a
narrow groove along 1 side, reddish brown or less commonly light brown or
nearly black. Seven to 8 species, native to Europe and Asia, introduced nearly
Species of Lolium are superficially similar to those
of the Elymus repens complex (tribe Triticeae) in their inflorescence
structure, but have the spikelets positioned with an edge toward the
inflorescence axis, whereas in the E. repens complex they are positioned
with a flat side next to the axis.