View source for Poa laxa ← Poa laxa You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=Poa laxa |accepted_authority= |publications= |basionyms= |synonyms= |hierarchy=Poaceae;Poaceae subfam. Pooideae;Poaceae tribe Poeae;Poa;Poa subg. Poa;Poa sect. Oreinos;Poa laxa |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 Poeae]]</div><div class="higher-taxon"><small>genus</small>[[Poa]]</div><div class="higher-taxon"><small>subgenus</small>[[Poa subg. Poa]]</div><div class="higher-taxon"><small>section</small>[[Poa sect. Oreinos]]</div><div class="higher-taxon"><small>species</small>[[Poa laxa]]</div></div> |volume=Volume 24 |mention_page= |treatment_page=page 572 }}<!-- --><span class="statement" id="st-d0_s0" data-properties=""><b>Plants </b>perennial;</span> <span class="statement" id="st-d0_s1" data-properties="">not or only slightly glaucous;</span> <span class="statement" id="st-d0_s2" data-properties="">densely tufted, not stoloniferous, not rhizomatous.</span> <span class="statement" id="st-d0_s3" data-properties="whole_organism duration;whole_organism pubescence;whole_organism arrangement or pubescence;whole_organism architecture;whole_organism architecture;whole_organism position;whole_organism architecture;whole_organism arrangement;whole_organism growth form"><b>Basal </b>branching mixed intra and extra vaginal.</span> <span class="statement" id="st-d0_s4" data-properties="culm some measurement;exserted node presence;exserted node atypical quantity"><b>Culms </b>6-18 cm, with 0 (1) exserted nodes, upper node in the lower 1/3 of the culms.</span> <span class="statement" id="st-d0_s5" data-properties="sheath length;sheath shape;sheath architecture or pubescence or relief;sheath pubescence or relief;distal sheath length"><b>Sheaths </b>closed for 1/10 – 1/5 their length, terete, smooth or very sparsely scabrous, distal sheath lengths 0.8-1.8 times blade lengths;</span> <span class="statement" id="st-d0_s6" data-properties="ligule some measurement;ligule architecture or pubescence or relief;apex shape;apex shape">ligules 1.25-2.5 mm, smooth, apices obtuse, often lacerate;</span> <span class="statement" id="st-d0_s7" data-properties="blade width;blade pubescence or relief;blade-leaf distance">blades thin, sparsely scabrous adaxially, flag leaf-blades 1.6-3.8 cm.</span> <span class="statement" id="st-d0_s8" data-properties="panicle some measurement;panicle architecture or arrangement;panicle shape;panicle condition or size;panicle density;branch quantity"><b>Panicles </b>1.5-3.5 cm, slightly lax, ovoid, contracted to loosely contracted, dense to moderately dense, with 2-6 branches per node;</span> <span class="statement" id="st-d0_s9" data-properties="branch orientation;branch course;branch architecture;branch shape;branch architecture or pubescence or relief;angle pubescence or relief;angle pubescence">branches steeply ascending, fairly straight, sulcate or angled, smooth or infrequently the angles sparsely scabrous, not glaucous.</span> <span class="statement" id="st-d0_s10" data-properties="spikelet shape"><b>Spikelets </b>laterally compressed;</span> <span class="statement" id="st-d0_s11" data-properties="floret quantity">florets 2-5;</span> <span class="statement" id="st-d0_s12" data-properties="rachilla internode architecture or pubescence or relief;rachilla internode pubescence;lower internode some measurement">rachilla internodes smooth, glabrous, lower internodes 0.8-1 mm.</span> <span class="statement" id="st-d0_s13" data-properties="glume variability;glume shape;glume width"><b>Glumes </b>equal, broadly lanceolate, thin;</span> <span class="statement" id="st-d0_s14" data-properties="lower glume width;lower glume architecture">lower glumes 0.75-1.05 mm wide, 3-veined;</span> <span class="statement" id="st-d0_s15" data-properties="upper glume length;upper glume width;upper glume l w ratio">upper glumes 3.7-4.7 mm long, 0.9-1.3 mm wide, lengths 3.7-4.1 times widths;</span> <span class="statement" id="st-d0_s16" data-properties="callus pubescence;spikelet pubescence">calluses all glabrous, or some proximal florets within a spikelet sparsely webbed;</span> <span class="statement" id="st-d0_s17" data-properties="lemma some measurement;lemma shape;lemma shape;lemma width;keel height or length or size;keel pubescence;marginal vein height or length or size;marginal vein pubescence;keel quantity;lateral-vein length;lateral-vein length;lateral-vein pubescence;lateral-vein pubescence;intercostal region pubescence">lemmas 3.7-4.5 mm, broadly lanceolate, distinctly keeled, thin, keels and marginal veins short to long-villous, hairs extending 1/3-1/2 the keel length, lateral-veins usually glabrous, or infrequently sparsely softly puberulent, intercostal regions glabrous;</span> <span class="statement" id="st-d0_s18" data-properties="palea keel pubescence or relief">palea keels finely scabrous;</span> <span class="statement" id="st-d0_s19" data-properties="anther some measurement">anthers 0.8-1.2 mm, poorly formed, sacs not fully maturing, not dehiscing, about 0.1 mm in diameter.</span> <span class="statement" id="st-d0_s20" data-properties="sac life cycle;sac dehiscence;sac diameter;2n chromosome quantity;2n chromosome quantity">2n = ca. 65, 70.</span><!-- -->{{Treatment/Body |discussion=<p>Poa laxa × glauca is an eastern low arctic entity which has passed under the name P. flexuosa Sm., P. laxa subsp. flexuosa (Sm.) Hyl., and, more recently, P. laxiuscula (Blytt) Lange. It has also been confused with P. glauca (p. 576). It can be distinguished from P. laxa (see previous) by its more open sheaths and poorly developed, indehiscent anthers. It differs from P. glauca in its broad, thin glumes and lemmas; compact panicles; smooth or nearly smooth, non-glaucous branches; and poorly developed, indehiscent anthers. It also grows in wetter habitats than P. glauca, often around seeps. Its chloroplast DNA is more like that of the American P. laxa subsp. fernaldiana than that of the European subspp. flexuosa and laxa or of P. glauca.</p> |tables= |references= }}<!-- --><!-- -->{{#Taxon: name=Poa laxa |authority= |rank=species |parent rank=section |synonyms= |basionyms= |family=Poaceae |reference=None |publication title= |publication year= |special status= |source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V24/V24_799.xml |subfamily=Poaceae subfam. Pooideae |tribe=Poaceae tribe Poeae |genus=Poa |subgenus=Poa subg. Poa |section=Poa sect. Oreinos |species=Poa laxa |2n chromosome quantity=70;65 |angle pubescence=not glaucous |angle pubescence or relief=scabrous |anther some measurement=0.8mm;1.2mm |apex shape=lacerate;obtuse |blade pubescence or relief=scabrous |blade width=thin |blade-leaf distance=1.6cm;3.8cm |branch architecture=sulcate |branch architecture or pubescence or relief=smooth |branch course=straight |branch orientation=ascending |branch quantity=2;6 |branch shape=angled |callus pubescence=glabrous |culm some measurement=6cm;18cm |distal sheath length=0.8-1.8 times blade lengths |exserted node atypical quantity=1 |exserted node presence=absent |floret quantity=2;5 |glume shape=lanceolate |glume variability=equal |glume width=thin |intercostal region pubescence=glabrous |keel height or length or size=short |keel pubescence=long-villous |keel quantity=1/3;1/2 |lateral-vein length=puberulent;glabrous |lateral-vein pubescence=puberulent;glabrous |lemma shape=keeled;lanceolate |lemma some measurement=3.7mm;4.5mm |lemma width=thin |ligule architecture or pubescence or relief=smooth |ligule some measurement=1.25mm;2.5mm |lower glume architecture=3-veined |lower glume width=0.75mm;1.05mm |lower internode some measurement=0.8mm;1mm |marginal vein height or length or size=short |marginal vein pubescence=long-villous |palea keel pubescence or relief=scabrous |panicle architecture or arrangement=lax |panicle condition or size=contracted;loosely contracted |panicle density=dense;moderately dense |panicle shape=ovoid |panicle some measurement=1.5cm;3.5cm |rachilla internode architecture or pubescence or relief=smooth |rachilla internode pubescence=glabrous |sac dehiscence=not dehiscing |sac diameter=0.1 |sac life cycle=maturing |sheath architecture or pubescence or relief=smooth |sheath length=closed |sheath pubescence or relief=scabrous |sheath shape=terete |spikelet pubescence=webbed |spikelet shape=compressed |upper glume l w ratio=3.7-4.1 |upper glume length=3.7mm;4.7mm |upper glume width=0.9mm;1.3mm |whole_organism architecture=branching;not rhizomatous;not stoloniferous |whole_organism arrangement=mixed |whole_organism arrangement or pubescence=tufted |whole_organism duration=perennial |whole_organism growth form=plant |whole_organism position=basal |whole_organism pubescence=glaucous }}<!-- -->[[Category:Treatment]][[Category:Poa sect. 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