Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Key to Lolium

Copy permalink to share

1 Inflorescence paniculate (spikelets borne on branches off the central axis, not 2-ranked).

2 Auricles ciliate (sometimes only very sparsely so – check several at 10-20× magnification); spikelets with 3-6 (-9) florets; old sheaths pale straw-colored, often remaining intact; internodes of the rachilla antrorsely scabrous  Lolium arundinaceum

2 Auricles glabrous; spikelets with (2-) 4-10 (-12) florets; old sheaths brown, decaying to fibers; internodes of the rachilla glabrous (smooth) or nearly so  Lolium pratense

1 Inflorescence spikelike (spikelets sessile on the central axis, 2-ranked).

3 Glumes (12-) 15-25 mm long, subcoriaceous, equaling or surpassing the uppermost lemma (therefore the length of the spikelet); florets 4-9 per spikelet; annual  Lolium temulentum ssp. temulentum

3 Glumes 4-12 mm long, herbaceous, shorter than the lemmas (therefore shorter than the spikelet); florets (2-) 5-22 per spikelet; annual or perennial.

Show caption*© Keith Bradley       4 Lemmas (at least the upper) awned, the awns to 15 mm long; florets 11-22 per spikelet; annual or perennial  Lolium multiflorum

Show caption*© Gary P. Fleming       4 Lemmas awnless; florets (2-) 5-10 per spikelet; perennial  Lolium perenne