{{Short description|Species of grass}} {{Speciesbox |image = Bromus squarrosus NRCS-1.jpg |image_caption = |genus = Bromus |species = squarrosus |authority = L. }}
'''''Bromus squarrosus''''', the '''rough brome''', is a brome grass native to Russia and Europe. The specific epithet ''squarrosus'' is Latin, meaning "with spreading tips". The grass has a diploid number of 14.
==Description==
''Bromus squarrosus'' is an annual grass, with culms growing {{convert|20-60|cm|abbr=on}} high. The culms are hollow and bear four to five leaves with sheaths shorter than the blades. The leaf sheaths are pubescent and the leaf blades are typically pubescent but occasionally glabrous. The leaf blades are {{convert|5-15|cm|abbr=on}} long and {{convert|4-6|mm|abbr=on}} wide. The prominent ragged ligules are shaggy and {{convert|1-1.5|mm|abbr=on}} long. The unilateral and lax panicles have few spreading or ascending branches that are erect in youth tend to nod at maturity. The racemose panicles are {{convert|7-20|cm|abbr=on}} long and {{convert|4-8|cm|abbr=on}} wide, and the branches are typically longer than the spikelets. The spikelets are typically solitary, lanceolate in youth and becoming more ovate at maturity, and are {{convert|2-4|cm|abbr=on}} long and {{convert|5-10|mm|abbr=on}} broad. The densely flowered spikelets bear ten to twenty flowers each, with the base of the florets hidden at maturity. The glumes can be smooth or scabrous. The lower glumes are three to five-veined and {{convert|4.5-7|mm|abbr=on}} long, and the upper glumes are seven-veined and {{convert|6-8|mm|abbr=on}} long. The unequal and ovate lemmas have nine faint nerves and broad translucent margins measuring as broad as {{convert|1|mm|abbr=on}}, and the lemmas do not roll inwards at maturity as other ''Bromus'' species typically would. The lemmas themselves are {{convert|8-11|mm|abbr=on}} long and {{convert|2-2.4|mm|abbr=on}} wide. The twisted and strongly divergent awns are {{convert|6-10|mm|abbr=on}} long. The small anthers are approximately {{convert|1|mm|abbr=on}} long and have notches at their ends. The caryopses are just as long as the paleas, and are flat or slightly rolled inwards.<ref name=Manual>{{cite book |title=Gray's Manual of Botany |author= Merrit Lyndon Fernald |year= 1970 |editor= R. C. Rollins |publisher= D. Van Nostrand Company |edition= Eighth (Centennial) - Illustrated|isbn= 0-442-22250-5 |page= 103}}</ref><ref name=Flora>{{cite book |title= Flora of North America: North of Mexico |volume= 24 |author= Flora of North America Editorial Committee |publisher= Oxford University Press |year= 1993 |isbn= 9780195310719 |page= 237}}</ref>
The long nine-ribbed palea and the oblong spikelets morphologically distinguish the species from most other ''Bromus'' species.<ref>{{cite book |title= The Grasses of Britain |url= https://archive.org/details/grassesofbritain00parn |author= Richard Parnell |publisher= William Blackwood and Sons |year= 1845 |page= 280-281}}</ref>
The grass flowers in June and July.
==Habitat and distribution==
''Bromus squarrosus'' grows in overgrazed pastures, fields, and road verges. It prefers loamy or alluvial soils. It is native to central Russia and southern Europe, but is naturalized throughout southern Canada and the northern United States.<ref name=Flora/><ref>{{cite book |title= CRC World Dictionary of Grasses: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology |author= Umberto Quattrocchi |publisher= CRC Press |year= 2006 |isbn= 9781420003222 |page= 391}}</ref>
==References== {{Reflist}}
{{Taxonbar|from=Q10888829}}
squarrosus Category:Plants described in 1753 Category:Botanical taxa named by Carl Linnaeus Category:Grasses of Lebanon