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=Haenke |publications= |common_names=Lax bluegrass |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 570 }}<!-- --><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 position;whole_organism position;whole_organism position;whole_organism growth form"><b>Basal </b>branching mixed, mainly extravaginal or mainly pseudointravaginal, sometimes intravaginal.</span> <span class="statement" id="st-d0_s4" data-properties="culm height;culm thickness;culm orientation;culm size"><b>Culms </b>8-35 cm tall, 0.5-0.9 mm thick, ascending to erect, slender;</span> <span class="statement" id="st-d0_s5" data-properties="node shape;node presence;node atypical quantity;node position">nodes terete, 0 (1) exserted.</span> <span class="statement" id="st-d0_s6" data-properties="sheath length;sheath shape;sheath architecture or pubescence or relief;sheath pubescence;base pubescence"><b>Sheaths </b>closed for 1/5-1/3 their length, terete, smooth, glabrous, bases of basal sheaths glabrous;</span> <span class="statement" id="st-d0_s7" data-properties="collar pubescence;collar pubescence;collar pubescence">collars smooth or scabrous, glabrous;</span> <span class="statement" id="st-d0_s8" data-properties="ligule some measurement;ligule architecture or pubescence or relief;apex shape;apex shape">ligules 2-4 mm, smooth, apices acute, often lacerate;</span> <span class="statement" id="st-d0_s9" data-properties="">innovation blades similar to the cauline blades;</span> <span class="statement" id="st-d0_s10" data-properties="cauline blade width;cauline blade width;cauline blade prominence or shape;cauline blade width;cauline blade pubescence or texture;cauline blade architecture or pubescence or relief;cauline blade architecture;blade size">cauline blades 1-2 (3) mm wide, flat, thin, soft, smooth, narrowly prow-tipped, blades not strongly graduated or reduced upwards.</span> <span class="statement" id="st-d0_s11" data-properties="panicle some measurement;panicle architecture or arrangement;panicle condition or size;panicle count or density;panicle condition or size;panicle density"><b>Panicles </b>2-8 cm, slightly lax, usually loosely contracted and sparse, infrequently contracted and dense;</span> <span class="statement" id="st-d0_s12" data-properties="branch atypical quantity;branch quantity">nodes with 1-3 (5) branches;</span> <span class="statement" id="st-d0_s13" data-properties="branch atypical some measurement;branch some measurement;branch orientation;branch orientation;branch orientation;branch course;branch course;branch size;branch architecture;branch shape;branch architecture or pubescence or relief;angle pubescence or relief;spikelet quantity">branches 1-3 (4) cm, usually ascending or weakly spreading, infrequently erect, fairly straight or flexuous, slender, sulcate or angled, smooth or the angles sparsely scabrous, with 1-8 spikelets.</span> <span class="statement" id="st-d0_s14" data-properties="spikelet some measurement;spikelet l w ratio;spikelet shape"><b>Spikelets </b>4-6 mm, lengths to 3 times widths, laterally compressed;</span> <span class="statement" id="st-d0_s15" data-properties="floret quantity">florets 2-5;</span> <span class="statement" id="st-d0_s16" data-properties="rachilla internode some measurement;rachilla internode architecture or pubescence or relief;rachilla internode pubescence">rachilla internodes shorter than 1 mm, smooth, glabrous.</span> <span class="statement" id="st-d0_s17" data-properties="glume variability;glume length or size;glume shape;glume width;glume shape;lemma arrangement;keel architecture or pubescence or relief;keel pubescence or relief"><b>Glumes </b>nearly equaling or slightly longer than the adjacent lemmas, lanceolate to broadly lanceolate, thin, distinctly keeled, keels smooth or sparsely scabrous;</span> <span class="statement" id="st-d0_s18" data-properties="lower glume architecture">lower glumes 1-3-veined;</span> <span class="statement" id="st-d0_s19" data-properties="upper glume height or length or size;lowest lemma size">upper glumes shorter than or subequal to the lowest lemmas;</span> <span class="statement" id="st-d0_s20" data-properties="callus pubescence;callus pubescence;hair height or length or size;hair length;lemma quantity">calluses glabrous or webbed, hairs usually shorter than 1/4 the lemma length, sparse;</span> <span class="statement" id="st-d0_s21" data-properties="lemma some measurement;lemma shape;lemma width;lemma shape;keel height or length or size;keel pubescence;marginal vein height or length or size;marginal vein pubescence;lateral-vein pubescence;lateral-vein pubescence;lateral-vein prominence;intercostal region pubescence;margin pubescence;apex shape">lemmas 3-4.6 mm, lanceolate to broadly lanceolate, thin, distinctly keeled, keels and marginal veins short to long-villous, lateral-veins glabrous or sparsely softly puberulent, lateral-veins obscure, intercostal regions glabrous, margins glabrous, apices acute;</span> <span class="statement" id="st-d0_s22" data-properties="palea pubescence or relief">paleas sparsely scabrous over the keels;</span> <span class="statement" id="st-d0_s23" data-properties="">anthers (0.6) 0.8-1.1 (1.3) mm.</span> <span class="statement" id="st-d0_s24" data-properties="anther atypical some measurement;anther some measurement;2n chromosome quantity;2n chromosome quantity;2n chromosome quantity">2n = 28, 42, 84.</span><!-- -->{{Treatment/Body |distribution=Maine;N.H.;Colo.;N.Y.;Vt.;Mont.;Oreg.;Wyo.;Alta.;B.C.;Nfld. and Labr.;Que. |discussion=<p>Poa laxa is a low arctic to high alpine amphiatlantic species. It has been treated as a series of separate species, but the differences seem relatively minor and incomplete. Its short anthers and smoother branches usually distinguish it from P. glauca (p. 576), with which it can hybridize to form P. laxa x glauca (p. 572).</p><!-- --><p>Poa laxa has four subspecies, two of which are native to the Flora region; subsp. laxa grows in central Europe; and subsp. flexuosa (Sm.) Hyl. in northwestern Europe.</p> |tables= |references= }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Innovations primarily extravaginal; panicle branches fairly straight; calluses glabrous |[[Poa laxa subsp. banffiana|Poa laxa subsp. banffiana]] |-id=key-0-1 |1 |Innovations primarily intravaginal; panicle branches flexuous, usually at least some florets having a webbed callus |[[Poa laxa subsp. fernaldiana|Poa laxa subsp. fernaldiana]] |} </div></div><!-- -->{{#Taxon: name=Poa laxa |authority=Haenke |rank=species |parent rank=section |synonyms= |basionyms= |family=Poaceae |illustrator=Sandy Long |illustration copyright=Utah State University |distribution=Maine;N.H.;Colo.;N.Y.;Vt.;Mont.;Oreg.;Wyo.;Alta.;B.C.;Nfld. and Labr.;Que. |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_796.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=84;42;28 |angle pubescence or relief=scabrous |anther atypical some measurement=0.6 |anther some measurement=0.8mm;1.1mm |apex shape=acute;lacerate;acute |base pubescence=glabrous |blade size=reduced |branch architecture=sulcate |branch architecture or pubescence or relief=smooth |branch atypical quantity=5 |branch atypical some measurement=4 |branch course=flexuous;straight |branch orientation=erect;spreading;ascending |branch quantity=1;3 |branch shape=angled |branch size=slender |branch some measurement=1cm;3cm |callus pubescence=webbed;glabrous |cauline blade architecture=prow-tipped |cauline blade architecture or pubescence or relief=smooth |cauline blade prominence or shape=flat |cauline blade pubescence or texture=soft |cauline blade width=thin;1mm;2mm |collar pubescence=glabrous;scabrous;smooth |culm height=8cm;35cm |culm orientation=ascending;erect |culm size=slender |culm thickness=0.5mm;0.9mm |floret quantity=2;5 |glume length or size=slightly longer |glume shape=keeled;lanceolate;broadly lanceolate |glume variability=equaling |glume width=thin |hair height or length or size=usually shorter |hair length=sparse |intercostal region pubescence=glabrous |keel architecture or pubescence or relief=smooth |keel height or length or size=short |keel pubescence=long-villous |keel pubescence or relief=scabrous |lateral-vein prominence=obscure |lateral-vein pubescence=puberulent;glabrous |lemma arrangement=adjacent |lemma quantity=1/4 |lemma shape=keeled;lanceolate;broadly lanceolate |lemma some measurement=3mm;4.6mm |lemma width=thin |ligule architecture or pubescence or relief=smooth |ligule some measurement=2mm;4mm |lower glume architecture=1-3-veined |lowest lemma size=subequal |margin pubescence=glabrous |marginal vein height or length or size=short |marginal vein pubescence=long-villous |node atypical quantity=1 |node position=exserted |node presence=absent |node shape=terete |palea pubescence or relief=scabrous |panicle architecture or arrangement=lax |panicle condition or size=contracted;contracted |panicle count or density=sparse |panicle density=dense |panicle some measurement=2cm;8cm |rachilla internode architecture or pubescence or relief=smooth |rachilla internode pubescence=glabrous |rachilla internode some measurement=1 |sheath architecture or pubescence or relief=smooth |sheath length=closed |sheath pubescence=glabrous |sheath shape=terete |spikelet l w ratio=0-3 |spikelet quantity=1;8 |spikelet shape=compressed |spikelet some measurement=4mm;6mm |upper glume height or length or size=shorter |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=intravaginal;pseudointravaginal;extravaginal;basal |whole_organism pubescence=glaucous }}<!-- -->[[Category:Treatment]][[Category:Poa sect. Oreinos]] Templates used on this page: Template:Poaceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/ID (view source) Return to Poa laxa.