{{Short description|Species of grass}} {{Speciesbox |image = |genus = Bromus |species = pacificus |authority = Shear }}
'''''Bromus pacificus''''', the '''Pacific brome''', is a perennial grass native to the Pacific coast of North America. ''Bromus pacificus'' has a diploid number of 28.
==Taxonomy==
''Bromus pacificus'' is often misidentified as various species of ''Bromus'' sect. ''Ceratochloa'', including ''B. carinatus'' and ''B. sitchensis''. B. pacificus resembles these species with its large and open panicles, but its lemmas are rounded or slightly keeled as compared to the flattened lemmas of ''B.'' sect. ''Ceratochloa''. In addition, ''B. pacificus'' typically occurs only near the coast of British Columbia while species of ''B.'' sect. ''Ceratochloa'' are more widely distributed, including habitats in California where ''B. pacificus'' has been misidentified.<ref name=Texas/>
==Description==
''Bromus pacificus'' lacks rhizomes and grows {{convert|45-172|cm|abbr=on}} tall. The smooth culms are {{convert|4-5|mm|abbr=on}} wide at their base and have five to nine nodes. The brownish culms are relatively pubescent, with hairs up to {{convert|1|mm|abbr=on}} long, though culms are occasionally glabrous with hairs only adjacent to nodes. The leaf sheaths remain closed for most of their length, being open for only {{convert|14-35|mm|abbr=on}}. Leaf sheaths are glabrous or pilose with hairs {{convert|2.1|mm|abbr=on}} long, and lack auricles. The membranous and glabrous ligules are {{convert|2-4|mm|abbr=on}} long. Leaf blades are {{convert|32-37|cm|abbr=on}} long and {{convert|7-16|mm|abbr=on}} wide, with an adaxial surface covered with hairs up to {{convert|1.5|mm|abbr=on}} long and a glabrous abaxial surface. Margins are smooth or slightly serrated. The open panicles are {{convert|17-28|cm|abbr=on}} long and {{convert|12.5-19|cm|abbr=on}} wide, with spreading or nodding branches. The spikelets are {{convert|2.1-3.8|cm|abbr=on}} long and number one to six per branch. The rachillas can sometimes be visible at maturity. Spikelets have six to eight florets. Glumes are pubescent, with hairs up to {{convert|0.6|mm|abbr=on}} long. The one-nerved lower glumes are {{convert|8.2-10.5|mm|abbr=on}} long, and the three-nerved upper glumes are {{convert|9.7-12|mm|abbr=on}} long. The seven-nerved lemmas are {{convert|10-13.5|mm|abbr=on}} long and {{convert|1.8-2.3|mm|abbr=on}} wide, and are covered with appressed hairs up to {{convert|1.5|mm|abbr=on}} long. Awns are {{convert|3-6.5|mm|abbr=on}} long. Paleas are typically shorter than lemmas, being {{convert|9-10|mm|abbr=on}} long, with dense cilia up to {{convert|0.5|mm|abbr=on}} long. The dark brown anthers are {{convert|2-3|mm|abbr=on}} long.<ref name=Texas>{{cite journal |title= TAXONOMY OF BROMUS (POACEAE: POOIDEAE: BROMEAE) SECTIONS BROMOPSIS, BROMUS, AND GENEA IN BRITISH COLUMBIA, CANADA |journal= Journal of the Botanical Research Institute of Texas |volume= 2 |publisher= Fort Worth, Texas: Botanical Research Institute of Texas |author= Saarela, Jeffery M. |year= 2008|url= https://www.biodiversitylibrary.org/page/41650331#page/353/mode/1up|pages= 344–346}}</ref><ref>{{cite book |title= Flora of North America, North of Mexico: Volume 24: Magnoliophyta: Commelinidae (in Part): Poaceae, Part 1 |volume= 24 |editor= Mary E. Barkworth |editor2=Kathleen M. Capels |editor3=Sandy Long |edition= illustrated |publisher= OUP USA |year= 2006 |isbn= 9780195310719 |page= 218}}</ref>
==Distribution and habitat==
''Bromus pacificus'' occurs along the Pacific coast as its specific epithet indicates. It occurs from southeastern Alaska down to central Oregon; most often it occurs in the coast of British Columbia. Habitats include moist ravines, shaded forests, wet thickets, saline beaches, ditches, and road verges, from {{convert|0-50|m|abbr=on}} in elevation.<ref name=Texas/><ref>{{cite book |title= Manual of Grasses for North America |editor=Mary E. Barkworth |editor2=Laurel K. Anderton |editor3=Kathleen M. Capels |editor4=Sandy Long |editor5=Michael B. Piep |publisher= University Press of Colorado |year= 2007 |isbn= 9781457180989}}</ref>
==References== {{Reflist}}
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pacificus Category:Plants described in 1900