Canadian: Occurs in AB, BC, MB, ON, QC and SK (Brouillet et al. 2016Footnote 1).
Worldwide: Native to temperate Asia and southern tropical Asia (USDA-ARS 2016Footnote 2). In the United States, it is widespread in the upper midwest states of Montana and North Dakota (USDA-NRCS 2016Footnote 3).
Duration of life cycle
Seed or fruit type
Floret length: 7.0 - 11.8 mm
Floret width: 1.5 - 2.8 mm
Floret thickness: 1.3 - 2.0 mm
Awn length: up to 15.0 mm
Floret oblong, compressed
Lemmas are usually unawned
Rachilla is flat and generally held close to the palea
Habitat and Crop Association
Cultivated fields (especially spring cereals), gardens, railway lines, roadsides and disturbed areas (Holman et al. 2004Footnote 4, Darbyshire 2003Footnote 5).
Annual ryegrass (Lolium multiflorum)
Annual ryegrass has a similar oblong shape, straw-yellow colour and flattened rachilla as Persian darnel. It is often difficult to tell these species apart.
Annual ryegrass florets may curve towards the lemma, the rachilla may be held away from the palea, and the florets are usually awned.