View source for Polygonum

{{Treatment/ID
|accepted_name=Polygonum
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=1: 359. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 170. 1754
|year=1754
}}
|common_names=Knotweed
|basionyms=
|synonyms=
|hierarchy=Polygonaceae;Polygonaceae subfam. Polygonoideae;Polygonum
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Polygonaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Polygonaceae subfam. Polygonoideae]]</div><div class="higher-taxon"><small>genus</small>[[Polygonum]]</div></div>
|etymology=Greek poly, many, and gony, knee joint (traditional interpretation), or gone, seed (grammatically correct interpretation)
|volume=Volume 5
|mention_page=page 216, 217, 218, 479, 480, 481, 541, 548, 574, 589, 594
|treatment_page=page 547
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole_organism growth form;whole_organism duration;whole_organism architecture;whole_organism architecture;whole_organism reproduction;whole_organism growth form;whole_organism growth form"><b>Herbs,</b> shrubs, or subshrubs, annual (perennial in P. striatulum), homophyllous or heterophyllous, sometimes heterocarpic;</span> <span class="statement" id="st-d0_s1" data-properties="root texture;root texture">roots fibrous or woody.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem pubescence;stem architecture or pubescence or relief;stem relief"><b>Stems </b>prostrate to erect, glabrous, smooth or sometimes papillous-scabridulous.</span> <span class="statement" id="st-d0_s3" data-properties="leaf position;leaf arrangement;leaf architecture;leaf architecture"><b>Leaves </b>cauline, alternate (opposite in P. humifusum), petiolate or sessile;</span> <span class="statement" id="st-d0_s4" data-properties="ocreum coloration;ocreum coloration;ocreum coloration;ocreum shape;ocreum pubescence or texture;ocreum pubescence;ocreum dehiscence;ocreum dehiscence;distal part duration">ocrea with distal part persistent, often hyaline, white or silvery, 2-lobed, chartaceous, glabrous, disintegrating into fibers, or disintegrating completely;</span> <span class="statement" id="st-d0_s5" data-properties="petiole base architecture">petiole base articulated with ocrea or not;</span> <span class="statement" id="st-d0_s6" data-properties="blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;margin architecture or shape">blade linear, lanceolate, elliptic, ovate, or subround, margins entire.</span> <span class="statement" id="st-d0_s7" data-properties="inflorescence position;inflorescence position;inflorescence position or structure subtype;inflorescence shape;flower architecture or arrangement or growth form"><b>Inflorescences </b>axillary or axillary and terminal, spikelike, or flowers solitary;</span> <span class="statement" id="st-d0_s8" data-properties="peduncle presence">peduncle absent.</span> <span class="statement" id="st-d0_s9" data-properties="pedicel presence;pedicel presence"><b>Pedicels </b>present or absent.</span> <span class="statement" id="st-d0_s10" data-properties="flower reproduction;flower atypical quantity;flower quantity;base shape"><b>Flowers </b>bisexual, 1–7 (–10) per ocreate fascicle, base not stipelike;</span> <span class="statement" id="st-d0_s11" data-properties="perianth size;perianth coloration;perianth shape;perianth pubescence">perianth nonaccrescent, white or greenish white to pink, campanulate to urceolate, glabrous;</span> <span class="statement" id="st-d0_s12" data-properties="tepal quantity;tepal length;tepal architecture;tepal architecture;tepal architecture;tepal architecture;tepal growth form;inner tepal prominence or shape;outer tepal prominence or shape;outer tepal shape;outer tepal shape;inner tepal character;inner tepal character">tepals 5, connate 3–70% of their length, petaloid or sepaloid, monomorphic or, rarely, dimorphic, the inner usually flat, the outer flat or sometimes keeled and cucullate distally, sometimes of different length than the inner;</span> <span class="statement" id="st-d0_s13" data-properties="stamen quantity">stamens 3–8 (some may reduced to staminodes);</span> <span class="statement" id="st-d0_s14" data-properties="filament fusion;filament fusion;filament fusion;filament pubescence">filaments distinct, free or adnate to perianth-tube, glabrous;</span> <span class="statement" id="st-d0_s15" data-properties="anther coloration;anther coloration;anther shape">anthers whitish yellow, pink to purple or orange-pink, elliptic to oblong;</span> <span class="statement" id="st-d0_s16" data-properties="style atypical quantity;style quantity;style orientation;style fusion;style fusion">styles (2–) 3, mostly spreading, distinct or connate proximally;</span> <span class="statement" id="st-d0_s17" data-properties="stigma quantity;stigma architecture or shape">stigmas 2–3, capitate.</span> <span class="statement" id="st-d0_s18" data-properties="achene position;achene position;achene coloration;achene coloration;achene coloration;achene coloration;achene coloration;achene architecture;achene shape;achene pubescence"><b>Achenes </b>included or exserted, yellow-green, brown, or black, unwinged, (2–) 3-gonous, glabrous.</span> <span class="statement" id="st-d0_s19" data-properties=""><b>Seeds:</b> embryo curved.</span> <span class="statement" id="st-d0_s20" data-properties="embryo course;x chromosome quantity">x = 10.</span><!--

-->{{Treatment/Body
|distribution=Nearly worldwide
|discussion=<p>Species ca. 65 (33 in the flora).</p><!--
--><p>Two sections of Polygonum are recognized here. Section Polygonum is nearly cosmopolitan and best represented in north-temperate regions; sect. Duravia comprises species restricted to North America. K. Haraldson (1978) recognized both sections based on differences in stem morphology, petiole structure, and pollen morphology. J. C. Hickman (1984) described sect. Monticola and included in it species of sect. Duravia occurring mostly in montane habitats, with leaves articulated to the ocreae, one-veined, and not mucronate, proximal leaves lanceolate to round, and styles connate at their bases and neither hardened nor persistent. L.-P. Ronse Decraene and J. R. Akeroyd (1988) and L.-P. Ronse Decraene et al. (2000) included sect. Duravia in sect. Polygonum based on floral and fruit characters.</p><!--
--><p>Similarities in floral structure, fruit anatomy, and pollen morphology have been noted between Polygonella with Polygonum (L.-P. Ronse Decraene et al. 2000). Based on evidence from comparative morphological studies, Ronse Decraene et al. (2004) included Polygonella in sect. Duravia of Polygonum.</p><!--
--><p>Four introduced taxa of sect. Polygonum that were collected in the flora area at the end of the nineteenth century and beginning of the twentieth century appear not to have persisted here and are not included in the keys. Polygonum arenarium Waldstein & Kitaibel and P. bellardii Allioni were reported by B. L. Robinson (1902) from Rhode Island and Massachusetts, respectively. The former resembles P. patulum but has open flowers. Polygonum bellardii is discussed below under P. ramosissimum. Polygonum polycnemoides Jaubert & Spach and P. humifusum C. Merck ex K. Koch subsp. humifusum were reported by J. F. Brenckle (1941). The former was collected in New York City in 1894 and in Idaho in 1940. It differs from all other Polygonum species in having a tube 55–70% of the perianth length. Polygonum humifusum subsp. humifusum is discussed below under P. humifusum subsp. caurianum.</p>
|tables=
|references={{Treatment/Reference
|id=jones1970a
|text=Jones, D. M. and T. R. Mertens. 1970. A taxonomic study of genus Polygonum employing chromatographic methods. Proc. Indiana Acad. Sci. 80: 422–430.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  <h3 class="treatment-key-header" id="key-0">Key to the Sections of Polygonum</h3>
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems distinctly and ± regularly 8-16-ribbed; leaf blade venation pinnate, secondary veins conspicuous; anthers whitish yellow; nearly worldwide
|[[Polygonum sect. Polygonum|Polygonum sect. Polygonum]]
|-id=key-0-1
|1
|Stems 4-gonous, ribs obscure or absent; leaf blade venation parallel, secondary veins not conspicuous; anthers pink to purple; mostly w North America
|[[Polygonum sect. Duravia|Polygonum sect. Duravia]]
|}
</div></div><!--

-->{{#Taxon:
name=Polygonum
|author=Mihai Costea;François J. Tardif;Harold R. Hinds†
|authority=Linnaeus
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=
|family=Polygonaceae
|illustrator=Yevonn Wilson-Ramsey
|illustration copyright=Flora of North America Association
|distribution=Nearly worldwide
|reference=jones1970a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;1754
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V5/V5_1117.xml
|subfamily=Polygonaceae subfam. Polygonoideae
|genus=Polygonum
|achene architecture=unwinged
|achene coloration=black;brown;black;brown;yellow-green
|achene position=exserted;included
|achene pubescence=glabrous
|achene shape=(2-)3-gonous
|anther coloration=pink;purple or orange-pink
|anther shape=elliptic;oblong
|base shape=not stipelike
|blade shape=subround;ovate;subround;ovate;elliptic;lanceolate;linear
|distal part duration=persistent
|embryo course=curved
|filament fusion=adnate;free;distinct
|filament pubescence=glabrous
|flower architecture or arrangement or growth form=solitary
|flower atypical quantity=7;10
|flower quantity=1;7
|flower reproduction=bisexual
|inflorescence position=axillary;axillary
|inflorescence position or structure subtype=terminal
|inflorescence shape=spikelike
|inner tepal character=length;length
|inner tepal prominence or shape=flat
|leaf architecture=sessile;petiolate
|leaf arrangement=alternate
|leaf position=cauline
|margin architecture or shape=entire
|ocreum coloration=silvery;white;hyaline
|ocreum dehiscence=disintegrating;disintegrating
|ocreum pubescence=glabrous
|ocreum pubescence or texture=chartaceous
|ocreum shape=2-lobed
|outer tepal prominence or shape=flat
|outer tepal shape=cucullate;keeled
|pedicel presence=absent;absent
|peduncle presence=absent
|perianth coloration=greenish white;pink
|perianth pubescence=glabrous
|perianth shape=campanulate;urceolate
|perianth size=nonaccrescent
|petiole base architecture=articulated
|root texture=woody;fibrous
|stamen quantity=3;8
|stem architecture or pubescence or relief=smooth
|stem orientation=prostrate;erect
|stem pubescence=glabrous
|stem relief=papillous-scabridulous
|stigma architecture or shape=capitate
|stigma quantity=2;3
|style atypical quantity=2;3
|style fusion=connate;distinct
|style orientation=spreading
|style quantity=3
|tepal architecture=,;monomorphic;sepaloid;petaloid
|tepal growth form=dimorphic
|tepal length=connate
|tepal quantity=5
|whole_organism architecture=heterophyllous;homophyllous
|whole_organism duration=annual
|whole_organism growth form=subshrub;shrub;herb
|whole_organism reproduction=heterocarpic
|x chromosome quantity=10
}}<!--

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