treatments-xml/data/89/29/4A/89294A68E5105948A4608C2D0091F6F8.xml

<document ID-DOI="http://dx.doi.org/10.3897/phytokeys.15.3084" ID-PMC="PMC3492929" ID-Pensoft-Pub="1314-2003-15-1" ID-Pensoft-UUID="FF9AC356FFDAFB26FF95FFE3FFA1520C" ID-PubMed="23185125" ID-Zenodo-Dep="576134" ModsDocID="1314-2003-15-1" checkinTime="1451251993896" checkinUser="pensoft" docAuthor="Soreng, Robert J. &amp; Peterson, Paul M." docDate="2012" docId="89294A68E5105948A4608C2D0091F6F8" docLanguage="en" docName="PhytoKeys 15: 1-104" docOrigin="PhytoKeys 15" docPubDate="2012-08-06" docSource="http://dx.doi.org/10.3897/phytokeys.15.3084" docTitle="Poa pratensis L., Sp. Pl. 1: 67 - 68 1753" docType="treatment" docVersion="3" id="FF9AC356FFDAFB26FF95FFE3FFA1520C" lastPageNumber="46" masterDocId="FF9AC356FFDAFB26FF95FFE3FFA1520C" masterDocTitle="Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: new records, re-evaluation of P. ruprechtii, and two new species, P. palmeri and P. wendtii" masterLastPageNumber="104" masterPageNumber="1" pageNumber="43" updateTime="1668139833991" updateUser="ExternalLinkService">
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<mods:title>Revision of Poa L. (Poaceae, Pooideae, Poeae, Poinae) in Mexico: new records, re-evaluation of P. ruprechtii, and two new species, P. palmeri and P. wendtii</mods:title>
</mods:titleInfo>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Soreng, Robert J.</mods:namePart>
<mods:affiliation>Department of Botany, National Museum of Natural History, Smithsonian Institution Washington, DC, 20013 - 7012, USA</mods:affiliation>
</mods:name>
<mods:name type="personal">
<mods:role>
<mods:roleTerm>Author</mods:roleTerm>
</mods:role>
<mods:namePart>Peterson, Paul M.</mods:namePart>
<mods:affiliation>Department of Botany, National Museum of Natural History, Smithsonian Institution Washington, DC, 20013 - 7012, USA</mods:affiliation>
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<mods:title>PhytoKeys</mods:title>
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<mods:date>2012</mods:date>
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<mods:number>2012-08-06</mods:number>
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<mods:detail type="volume">
<mods:number>15</mods:number>
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<mods:url>http://dx.doi.org/10.3897/phytokeys.15.3084</mods:url>
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<treatment ID-GBIF-Taxon="182229290" LSID="urn:lsid:plazi:treatment:89294A68E5105948A4608C2D0091F6F8" httpUri="http://treatment.plazi.org/id/89294A68E5105948A4608C2D0091F6F8" lastPageId="45" lastPageNumber="46" pageId="42" pageNumber="43">
<subSubSection pageId="42" pageNumber="43" type="nomenclature">
<paragraph pageId="42" pageNumber="43">
16. 
<taxonomicName LSID="89294A68-E510-5948-A460-8C2D0091F6F8" authority="L., Sp. Pl. 1: 67 - 68, 1753." authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="Poa pratensis" order="Poales" pageId="42" pageNumber="43" phylum="Tracheophyta" rank="species" species="pratensis">Poa pratensis L., Sp. Pl. 1: 67-68, 1753.</taxonomicName>
<figureCitation captionStart="Figure 17" captionStartId="F17" captionText="Figure 17. Poa pratensis L. A-C Poa pratensis subsp. agassizensis (B. Boivin &amp; D. Loeve) Roy L. Taylor &amp; MacBryde A habit B sheath, ligule, blade lateral view C branch segment with spikelets D-G subsp. alpigena (Lindm.) Hiitonen D habit E inflorescence F branch segment with spikelets G palea H, I subsp. angustifolia (L.) Lej. H habit I branch segment with spikelets. Drawings from Soreng (2007)." httpUri="https://binary.pensoft.net/fig/10152" pageId="42" pageNumber="43">Fig. 17</figureCitation>
<figureCitation captionStart="Figure 18" captionStartId="F18" captionText="Figure 18. Poa pratensis L. A, B Poa pratensis subsp. irrigata (Lindm.) H. Lindb. A habit B spikelet C-J subsp. pratensis C habit D sheath, ligule blade lateral view E blade apex lateral view F blade apex adaxial view G inflorescence H branch segment with spikelets I spikelet J floret. Drawings from Soreng (2007)." httpUri="https://binary.pensoft.net/fig/10153" pageId="42" pageNumber="43">18</figureCitation>
</paragraph>
</subSubSection>
<subSubSection pageId="42" pageNumber="43" type="type">
<paragraph pageId="42" pageNumber="43">Type:</paragraph>
<paragraph pageId="42" pageNumber="43">
Russia, Prov. Sanct-Petersburg, 5 km australi-occidentum, 26 Jun 1997, 
<emphasis italics="true" pageId="42" pageNumber="43">N.N. Tzvelev N-257</emphasis>
(conserved type: BM! designated by 
<bibRefCitation author="Soreng, RJ" journalOrPublisher="Madrono" pageId="69" pageNumber="70" refId="B51" refString="Soreng, RJ, Barrie, FR, 1998. Proposal [1391] to conserve the name Poa pratensis (Poaceae) with a conserved type. Taxon 48(1): 157-159." title="Proposal [1391] to conserve the name Poa pratensis (Poaceae) with a conserved type. Taxon 48 (1): 157 - 159." year="1998">Soreng and Barrie 1998</bibRefCitation>
, 157; isotypes: B!, C!, CAN!, CONC!, H!, K!, KW!, L!, LE!, LIV!, MA!, MO!, MW!, NSW!, P!, PE!, PR!, S!, SI!, TNS!, US-3456252!, W!).
</paragraph>
</subSubSection>
<subSubSection lastPageId="44" lastPageNumber="45" pageId="42" pageNumber="43" type="description">
<paragraph pageId="42" pageNumber="43">Description.</paragraph>
<paragraph lastPageId="44" lastPageNumber="45" pageId="42" pageNumber="43">
Hermaphroditic. 
<emphasis bold="true" pageId="42" pageNumber="43">Perennials</emphasis>
; tufted or not, rhizomatous, shoots solitary or tufted in part, tufts of narrow to medium girth and low to medium height, 
<pageBreakToken pageId="43" pageNumber="44" start="start">sometimes</pageBreakToken>
forming a dense turf (as in lawns), green, bluish-green, or bluish-gray-green; tillers extravaginal (basally cataphyllous), or also intravaginal (each subtended by a single elongated, 2-keeled, longitudinally split prophyll), with lateral and downward tending, cataphyllous shoots. 
<emphasis bold="true" pageId="43" pageNumber="44">Culms</emphasis>
5-70(-100) cm tall, erect or bases decumbent, leafy, terete or weakly compressed, smooth; nodes terete or weakly compressed, 1-2(-3) nodes exposed, proximal node(s) usually not exerted. 
<emphasis bold="true" pageId="43" pageNumber="44">Leaf</emphasis>
sheaths terete to slightly compressed, glabrous or infrequently sparsely to moderately puberulent; butt sheaths papery, smooth, glabrous; flag leaf sheaths 2-20 cm long, margins fused 25-50% the length, 1.2-5(-6.2) 
<normalizedToken originalValue="×">x</normalizedToken>
long as its blade; collars smooth, glabrous or ciliate along the margins; ligules 0.9-2(-3.1) mm long, abaxially smooth or scabrous, upper margin ciliolate or glabrous, apices truncate to rounded, infrequently obtuse; blades of cauline leaves 0.4-4.5 mm wide, flat or folded, to involute on the margins, soft and lax to moderately firm, abaxially smooth, glabrous, adaxially smooth or lightly scabrous, frequently with sparse, slender, erect to appressed, curving, sinuous or strait hairs to 0.2-0.8 mm long, broadly prow-tipped or some narrowly prow-tipped; blades subequal, or middle blades longest, flag leaf blades 1.5-10 cm; sterile shoot blades of extravaginal shoots like those of the culm, of intravaginal shoots, when present, sometimes distinctly narrower (0.4-1 mm wide), flat to involute. 
<emphasis bold="true" pageId="43" pageNumber="44">Panicles</emphasis>
2-15(-20) cm long, erect or nodding, loosely contacted to open, narrowly ovoid to narrowly or broadly pyramidal, sparse to moderately congested, with (25-)30 to over 100 spikelets; rachis with (1-)2-7(-9) branches per node; primary branches spreading early or late, terete or angled, smooth or sparsely to moderately densely scabrous; lateral pedicels usually 1/5-1/2 the spikelet in length, smooth, or sparsely to moderately densely scabrous, prickles fairly fine; longest branches (1-)2-9 cm, with 4-30(-50) spikelets, spikelets usually fairly crowded in distal 1/2. 
<emphasis bold="true" pageId="43" pageNumber="44">Spikelets</emphasis>
3.5-6(-7) mm long, to 3.5 
<normalizedToken originalValue="×">x</normalizedToken>
long as wide, lanceolate to ovate, laterally compressed, sometimes bulbiferous; florets 2-5, infrequently bulbous basally and leaf-like distally, hermaphroditic; rachilla internodes terete, mostly less than 1 mm long, smooth, glabrous; glumes narrowly lanceolate to lanceolate, infrequently broadly lanceolate, unequal to subequal, usually distinctly shorter than the adjacent lemmas, distinctly keeled, keels sparsely to densely, usually moderately, scabrous, infrequently smooth, apex acute, to acuminate; lower glumes 1.5-4(-4.5) mm long, 1-3-veined, narrowly lanceolate, occasionally weakly sickle shaped; upper glumes 2-4.5(-5) mm long, distinctly shorter to nearly equaling lowest lemma, 3-veined; calluses dorsally webbed, web well developed, sometimes with secondary tufts under each marginal vein, hairs 2-4 mm long, woolly; lemmas 2-4.3(-6) mm long, lanceolate, green or strongly purple colored, distinctly keeled, keels and marginal veins long villous, intermediate veins glabrous or infrequently short villous to softly puberulent, between veins glabrous, smooth or finely muriculate, smooth or lightly scabrous above, intermediate veins prominent, margins narrowly to broadly hyaline, apices acute; paleas scabrous, medially sometimes softly puberulent over the keels, intercostal region narrow, glabrous, or rarely very sparsely and minutely hispidulous. 
<emphasis bold="true" pageId="43" pageNumber="44">Flowers</emphasis>
chasmogamous; lodicules 0.35-0.5(-0.7) mm 
<pageBreakToken pageId="44" pageNumber="45" start="start">long</pageBreakToken>
, broadly ovate, with a short lateral lobe about midpoint; anthers 1.2-2 mm long, infrequently aborted late in development and ca. 1 mm long. 
<emphasis bold="true" pageId="44" pageNumber="45">Caryopses</emphasis>
1.5-2 mm long, elliptical in side-view, slightly laterally compressed, subtrigonous in cross-section, brown, sulcus broad, shallow, hilum 0.2 mm long, round to oval, grain adherent to the palea. 2 
<emphasis italics="true" pageId="44" pageNumber="45">n</emphasis>
= 28-147.
</paragraph>
</subSubSection>
<subSubSection pageId="44" pageNumber="45" type="distribution">
<paragraph pageId="44" pageNumber="45">Distribution.</paragraph>
<paragraph pageId="44" pageNumber="45">
The species is distributed worldwide but absent from tropical countries except in high mountains, or where introduced. In Mexico, the species is known from Baja California, Chihuahua, Coahuila, Distrito Federal, Hidalgo, Mexico, Nuevo 
<normalizedToken originalValue="León">Leon</normalizedToken>
, San Luis 
<normalizedToken originalValue="Potosí">Potosi</normalizedToken>
and Veracruz. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="44" pageNumber="45" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="44" pageNumber="45">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">agassizensis</emphasis>
and subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">alpigena</emphasis>
are possibly native to Mexico.
</paragraph>
</subSubSection>
<subSubSection pageId="44" pageNumber="45" type="ecology">
<paragraph pageId="44" pageNumber="45">Ecology.</paragraph>
<paragraph pageId="44" pageNumber="45">The facultatively apomictic, mostly high polyploid species inhabits cool mesic to frigid climates, is often seeded for pastures and lawns, and is easily established outside of cultivation since it tolerates disturbance. In Mexico, it occurs from 10-3650 m. Flowering May to July.</paragraph>
</subSubSection>
<subSubSection lastPageId="45" lastPageNumber="46" pageId="44" pageNumber="45" type="discussion">
<paragraph pageId="44" pageNumber="45">Discussion.</paragraph>
<paragraph lastPageId="45" lastPageNumber="46" pageId="44" pageNumber="45">
Even though the species is highly plastic and tends to look a bit odd in low latitudes, we made an attempt to sort out the subspecific forms in Mexico. The results were unsatisfactory. We have identified a few specimens that match the typical forms, but we could not confidently place most of the material into subspecies. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="44" pageNumber="45" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="44" pageNumber="45">Poa pratensis</emphasis>
</taxonomicName>
is primarily a high polyploid and facultatively apomictic (
<bibRefCitation author="Clausen, J" journalOrPublisher="Euphytica" pageId="69" pageNumber="70" pagination="87 - 94" publicationUrl="10.1007/BF00037208" refId="B7" refString="Clausen, J, 1961. Introgression facilitated by apomixis in polyploid Poas. Euphytica 10: 87 - 94, 10.1007/BF00037208" title="Introgression facilitated by apomixis in polyploid Poas." url="10.1007/BF00037208" volume="10" year="1961">Clausen 1961</bibRefCitation>
). It is a common circumboreal species with numerous strains that are treated as species by some authors and as subspecies by others. In Russia (including the former Soviet States) the decision of whether to recognize the various morphological &quot;forms&quot; as subspecies or as distinct species has changed (
<bibRefCitation author="Tzvelev, NN" journalOrPublisher="Madrono" pageId="69" pageNumber="70" refId="B64" refString="Tzvelev, NN, 1976. Zlaki SSSR. Leningrad: Nauka Publishers [English translation: 1983. Grasses of the Soviet Union, Vol. 1 and 2. New Delhi: Oxonian Press]." title="Zlaki SSSR. Leningrad: Nauka Publishers [English translation: 1983. Grasses of the Soviet Union, Vol. 1 and 2. New Delhi: Oxonian Press]." year="1976">Tzvelev 1976</bibRefCitation>
, 
<bibRefCitation author="Czerepanov, SK" journalOrPublisher="Euphytica" pageId="69" pageNumber="70" refId="B10" refString="Czerepanov, SK, 1995. Vascular plants of Russia and adjacent states (the former USSR), Cambridge University Press, New York, 516 pp." title="Vascular plants of Russia and adjacent states (the former USSR), Cambridge University Press, New York, 516 pp." year="1995">Czerepanov 1995</bibRefCitation>
) in favor of species, while in the UK 
<bibRefCitation author="Cope, T" journalOrPublisher="Euphytica" pageId="69" pageNumber="70" refId="B9" refString="Cope, T, Gray, A, 2009. Grasses of the British Isles. B.S.B.I. Handbook No. 13. Botanical Society of the British Isles, London." title="Grasses of the British Isles. B. S. B. I. Handbook No. 13. Botanical Society of the British Isles, London." year="2009">Cope and Gray (2009)</bibRefCitation>
in the United Kingdom, and 
<bibRefCitation author="Portal, R" journalOrPublisher="Sida" pageId="69" pageNumber="70" refId="B39" refString="Portal, R, 2005. Poa de France Belgique et Suisse. Privately published in France, 303 pp." title="Poa de France Belgique et Suisse. Privately published in France, 303 pp." year="2005">Portal (2005)</bibRefCitation>
in France Belgium and Switzerland have gone with subspecies. 
<bibRefCitation author="Stoneberg-Holt, SD" journalOrPublisher="Madrono" pageId="69" pageNumber="70" refId="B61" refString="Stoneberg-Holt, SD, 2004. The trnL-F plastid DNA region and its application to phylogeographic analysis in Poa pratensis agg. Dissertation, Masaryk University, Czech Republic." title="The trnL-F plastid DNA region and its application to phylogeographic analysis in Poa pratensis agg. Dissertation, Masaryk University, Czech Republic." year="2004">Stoneberg-Holt (2004)</bibRefCitation>
correlated morphology and ploidy-level in samples of 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="44" pageNumber="45" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="44" pageNumber="45">Poa pratensis</emphasis>
</taxonomicName>
collected mainly across Eastern Europe and in Montana in the USA, and grown in a common garden with and without shade. She concluded that there was a continuum of morphological forms that grade from one extreme to another. Plants with predominantly very-fine, moderately firm (form retaining) intravaginal-leaved shoots, and low polyploidy (2n = 28-42) are referable to subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">angustifolia</emphasis>
; these grade into plants with some intravaginal-leaved shoots that are mostly soft-bladed and mainly of middle-ploidy (2n = 42-56) that are referable to subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">pratensis</emphasis>
; these grade into plants with all or most shoots extravaginal, fairly broad-bladed, of mainly higher ploidy (2n = 58-144) referable to subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">irrigata</emphasis>
. Selections by plant breeders from across the range of these forms are all evidently introduced into North America for pastures, soil stabilization, and lawns. However, the cultivated forms have been selected from forms attractive for lawns and most durable to mowing and trampling, and we are no longer dealing with geographic and ecologically differentiated natural taxa. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="44" pageNumber="45" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="44" pageNumber="45">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">alpigena</emphasis>
and subsp. 
<emphasis italics="true" pageId="44" pageNumber="45">agassizensis</emphasis>
are probably native and are primarily mid-range polyploids. Our key to subspecies is presented for heuristic purposes; however, in practice it is difficult to draw a firm line between the tax 
<pageBreakToken pageId="45" pageNumber="46" start="start">a</pageBreakToken>
.
</paragraph>
<caption httpUri="https://binary.pensoft.net/fig/10152" pageId="45" pageNumber="46" start="Figure 17" startId="F17">
<paragraph pageId="45" pageNumber="46">
<emphasis bold="true" pageId="45" pageNumber="46">Figure 17.</emphasis>
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
L. 
<emphasis bold="true" pageId="45" pageNumber="46">A-C</emphasis>
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">agassizensis</emphasis>
(B. Boivin &amp; D. 
<normalizedToken originalValue="Löve">Loeve</normalizedToken>
) Roy L. Taylor &amp; MacBryde 
<emphasis bold="true" pageId="45" pageNumber="46">A</emphasis>
habit 
<emphasis bold="true" pageId="45" pageNumber="46">B</emphasis>
sheath, ligule, blade lateral view 
<emphasis bold="true" pageId="45" pageNumber="46">C</emphasis>
branch segment with spikelets 
<emphasis bold="true" pageId="45" pageNumber="46">D-G</emphasis>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">alpigena</emphasis>
(Lindm.) Hiitonen 
<emphasis bold="true" pageId="45" pageNumber="46">D</emphasis>
habit 
<emphasis bold="true" pageId="45" pageNumber="46">E</emphasis>
inflorescence 
<emphasis bold="true" pageId="45" pageNumber="46">F</emphasis>
branch segment with spikelets 
<emphasis bold="true" pageId="45" pageNumber="46">G</emphasis>
palea 
<emphasis bold="true" pageId="45" pageNumber="46">H, I</emphasis>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">angustifolia</emphasis>
(L.) Lej. 
<emphasis bold="true" pageId="45" pageNumber="46">H</emphasis>
habit 
<emphasis bold="true" pageId="45" pageNumber="46">I</emphasis>
branch segment with spikelets. Drawings from 
<bibRefCitation author="Soreng, RJ" journalOrPublisher="Madrono" pageId="69" pageNumber="70" refId="B50" refString="Soreng, RJ, 2007. Poa L. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Flora of North America North of Mexico, vol. 24. Oxford University Press, New York, 486-601." title="Poa L. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Flora of North America North of Mexico, vol. 24. Oxford University Press, New York, 486 - 601." year="2007">Soreng (2007)</bibRefCitation>
.
</paragraph>
</caption>
<caption httpUri="https://binary.pensoft.net/fig/10153" pageId="45" pageNumber="46" start="Figure 18" startId="F18">
<paragraph pageId="45" pageNumber="46">
<emphasis bold="true" pageId="45" pageNumber="46">Figure 18.</emphasis>
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
L. 
<emphasis bold="true" pageId="45" pageNumber="46">A, B</emphasis>
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">irrigata</emphasis>
(Lindm.)H. Lindb. 
<emphasis bold="true" pageId="45" pageNumber="46">A</emphasis>
habit 
<emphasis bold="true" pageId="45" pageNumber="46">B</emphasis>
spikelet 
<emphasis bold="true" pageId="45" pageNumber="46">C-J</emphasis>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">pratensis</emphasis>
<emphasis bold="true" pageId="45" pageNumber="46">C</emphasis>
habit 
<emphasis bold="true" pageId="45" pageNumber="46">D</emphasis>
sheath, ligule blade lateral view 
<emphasis bold="true" pageId="45" pageNumber="46">E</emphasis>
blade apex lateral view 
<emphasis bold="true" pageId="45" pageNumber="46">F</emphasis>
blade apex adaxial view 
<emphasis bold="true" pageId="45" pageNumber="46">G</emphasis>
inflorescence 
<emphasis bold="true" pageId="45" pageNumber="46">H</emphasis>
branch segment with spikelets 
<emphasis bold="true" pageId="45" pageNumber="46">I</emphasis>
spikelet 
<emphasis bold="true" pageId="45" pageNumber="46">J</emphasis>
floret. Drawings from 
<bibRefCitation author="Soreng, RJ" journalOrPublisher="Madrono" pageId="69" pageNumber="70" refId="B50" refString="Soreng, RJ, 2007. Poa L. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Flora of North America North of Mexico, vol. 24. Oxford University Press, New York, 486-601." title="Poa L. In: Barkworth ME, Capels KM, Long S, Piep MB (Eds) Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Flora of North America North of Mexico, vol. 24. Oxford University Press, New York, 486 - 601." year="2007">Soreng (2007)</bibRefCitation>
.
</paragraph>
</caption>
</subSubSection>
<subSubSection pageId="45" pageNumber="46" type="key to the subspecies of poa pratensis">
<paragraph pageId="45" pageNumber="46">
Key to the subspecies of 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
</paragraph>
<paragraph pageId="45" pageNumber="46">
<table inLine="true" pageId="45" pageNumber="46">
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">1</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Vegetative shoots intravaginal (each with a well-developed, 2-keeled, longitudinally-spilt prophyll), and extravaginal shoots (each with a rudimentary prophyll and one to several cataphylls at the base); the involute blades often distinctly narrower than the flat ones</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">2</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">-</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Vegetative shoots all extravaginal (or infrequently also with an intravaginal shoot), isolated or crowded (each extravaginal shoot with a rudimentary prophyll, and one to several cataphylls at the base)</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">4</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">2</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Blades mostly flat and fairly soft, or a mixture of folded-involute moderately-soft to soft vegetative shoot blades, and flat or folded, soft culm blades; the adaxial surfaces of all blades usually glabrous; abaxial veins of intravaginal shoot blades slender, narrower than the intercostal surfaces; plants of pastures and parks and waste ground to subalpine</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
6e. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">pratensis</emphasis>
</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">-</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Blades of vegetative and culm shoots involute on the margins, moderately firm, and of fairly uniform width; the adaxial surfaces, at least of the vegetative shoot blades with sparse, elongated, weakly-appressed hairs; abaxial veins of intravaginal shoot blades slender to thick, narrower to broader than the intercostal surfaces; plants widespread</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">3</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">3</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Blades ca. (0.8-) 1-2 mm wide (expanded), the longer vegetative shoot blades short less than 10 (-15) long; panicles contracted, branches smooth or sparsely scabrous; plants of mountain meadows, open forests, and subalpine</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
16a. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">agassizensis</emphasis>
</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">-</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Blades 0.4-1 mm wide (expanded), the longer vegetative shoot blades often exceeding 10 cm long; panicles loosely contracted to open, branches usually scabrous; plants of pastures, waste ground</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
16c. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">angustifolia</emphasis>
</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">4</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Extravaginal shoot blades fairly slender (1-2 mm wide), usually folded; vegetative shoots mostly isolated; panicles narrowly pyramidal, branches mostly smooth or sparsely scabrous, spikelets 3-4.5 mm long; plants of subalpine to alpine</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
16b. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">alpigen</emphasis>
a
</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">-</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Extravaginal shoot blades generally broader (2-5 mm wide), flat or folded, often lax; vegetative shoots isolated or crowded; panicles pyramidal to broadly pyramidal, branches somewhat sparsely to fairly densely scabrous; spikelets 4-7 mm long; plants of lawns and parks and waste ground to low alpine</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">5</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">5</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Glumes subequal, frequently pruinose, lower glumes (1) 3-viened, similar in shape to the upper glume, upper glumes often equal to the lowest lemma in length; panicles fairly sparsely flowered; collar margins and ligule abaxial surfaces commonly pubescent</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
16d. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">irrigata</emphasis>
</td>
</tr>
<tr pageId="45" pageNumber="46">
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">-</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">Glumes unequal, infrequently pruinose, lower glumes 1 (3)-veined, narrower than the upper glume, upper glumes usually shorter than lowest lemma; panicles moderately densely flowered; collar margins and ligule abaxial surfaces usually glabrous</td>
<td colspan="1" pageId="45" pageNumber="46" rowspan="1">
16e. 
<taxonomicName authorityName="L., Sp. Pl. 1: 67 - 68" authorityYear="1753" class="Liliopsida" family="Poaceae" genus="Poa" higherTaxonomySource="CoL" kingdom="Plantae" lsidName="" order="Poales" pageId="45" pageNumber="46" phylum="Tracheophyta" rank="species" species="pratensis">
<emphasis italics="true" pageId="45" pageNumber="46">Poa pratensis</emphasis>
</taxonomicName>
subsp. 
<emphasis italics="true" pageId="45" pageNumber="46">pratensis</emphasis>
</td>
</tr>
</table>
</paragraph>
</subSubSection>
</treatment>
</document>