View source for Achnatherum occidentale

{{Treatment/ID
|accepted_name=Achnatherum occidentale
|accepted_authority=(Thurb.) Barkworth
|publications=
|special_status={{Treatment/ID/Special_status
|code=E
|label=Endemic
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Stipa occidentalis
|authority=
|rank=species
}} {{Treatment/ID/Synonym
|name=Stipa occidentalis var. montana
|authority=
|rank=variety
}}
|hierarchy=Poaceae;Poaceae subfam. Pooideae;Poaceae tribe Stipeae;Achnatherum;Achnatherum occidentale
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Poaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Poaceae subfam. Pooideae]]</div><div class="higher-taxon"><small>tribe</small>[[Poaceae tribe Stipeae]]</div><div class="higher-taxon"><small>genus</small>[[Achnatherum]]</div><div class="higher-taxon"><small>species</small>[[Achnatherum occidentale]]</div></div>
|volume=Volume 24
|mention_page=
|treatment_page=page 121
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>tightly cespitose, not rhizomatous. <b>Culms</b> 14-120(180) cm tall, 0.3-2 mm thick, internodes glabrous or puberulent to densely pubescent; nodes 2-4, glabrous or pubescent. <b>Basal</b> sheaths glabrous or puberulent to densely pubescent, often ciliate at the throat; collars often with tufts of hair at the sides; ligules 0.2-1.5 mm, often ciliate; blades 0.5-3 mm wide and flat, or convolute and 0.1-0.8 mm in diameter, lax to straight. <b>Panicles</b> 5-30 cm long, 0.5-1.5 cm wide; branches appressed, straight, longest branches 1-7 cm. <b>Spikelets</b> appressed to the branches. <b>Glumes</b> subequal, 9-15 mm long, 0.6-0.9 mm wide; florets 5.5-7.5 mm long, 0.5-0.9 mm thick, fusiform, terete; calluses 0.8-1.2 mm, sharp, dorsal boundary of the glabrous tip with the callus hairs narrowly acute; lemmas evenly hair, hairs 0.5-1.5 mm at midlength, apical hairs somewhat longer than those below, sometimes similar in length to those at the base of the awns, sometimes longer, apical lobes 0.3-0.5 mm, membranous; awns 15-55 mm, twice-geniculate, first 2 segments evidently hairy, terminal segment glabrous or partly to wholly pilose, sometimes scabrous; paleas 2.2-3.5 mm, 2/5 – 3/5 as long as the lemmas, hairs at the tip usually shorter than 1 mm, frequently extending beyond the apices, apices rounded; anthers 2.5-3.5 mm, dehiscent, not penicillate. <b>Caryopses</b> 4-6 mm, fusiform. <b>2n</b> =36.</span><!--

-->{{Treatment/Body
|distribution=Utah;Wash.;Colo.;Mont.;Alta.;B.C.;Idaho;Calif.;Wyo.;Ariz.;Nev.;Oreg.
|discussion=<p><i>Achnatherum occidentale</i>, which extends from British Columbia to California, Utah, and Colorado, varies considerably in pubescence and size. The three subspecies recognized here occasionally occur together.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Terminal awn segment usually pilose; culms 0.3-1 mm thick, glabrous even on the basal internodes; glumes often purplish
|[[Achnatherum occidentale subsp. occidentale|Achnatherum occidentale subsp. occidentale]]
|-id=key-0-1
|1
|Terminal awn segment usually scabrous or glabrous, occasionally pilose at the base; culms 0.5-2 mm thick; glumes usually green.
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|First 2 awn segments scabrous or pilose with hairs of mixed lengths; apical lemma hairs longer than the basal awn hairs
|[[Achnatherum occidentale subsp. californicum|Achnatherum occidentale subsp. californicum]]
|-id=key-0-2
|2
|First 2 awn segments pilose, the hairs gradually and evenly becoming shorter towards the first geniculation; apical lemma hairs similar in length to the basal awn hairs
|[[Achnatherum occidentale subsp. pubescens|Achnatherum occidentale subsp. pubescens]]
|}
</div></div><!--

-->{{#Taxon:
name=Achnatherum occidentale
|authority=(Thurb.) Barkworth
|rank=species
|parent rank=genus
|synonyms=Stipa occidentalis;Stipa occidentalis var. montana
|basionyms=
|family=Poaceae
|illustrator=Cindy Roché
|illustration copyright=Utah State University
|distribution=Utah;Wash.;Colo.;Mont.;Alta.;B.C.;Idaho;Calif.;Wyo.;Ariz.;Nev.;Oreg.
|reference=None
|publication title=
|publication year=
|special status=Endemic
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-data-curation.git/src/bb6b7e3a7de7d3b7888a1ad48c7fd8f5c722d8d6/coarse_grained_fna_xml/V24/V24_149.xml
|subfamily=Poaceae subfam. Pooideae
|tribe=Poaceae tribe Stipeae
|genus=Achnatherum
|species=Achnatherum occidentale
}}<!--

-->[[Category:Treatment]][[Category:Achnatherum]]