View source for Arctium

{{Treatment/ID
|accepted_name=Arctium
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 816. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 357. 1754
|year=1754
}}
|common_names=Burdock;clotbur;bardane
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Cardueae;Arctium
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Cardueae]]</div><div class="higher-taxon"><small>genus</small>[[Arctium]]</div></div>
|etymology=Greek arktion, from arktos, bear, perhaps alluding to rough involucre
|volume=Volume 19
|mention_page=page 28, 58, 83, 169
|treatment_page=page 168
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole-organism some measurement;whole-organism duration;whole-organism some measurement;whole-organism duration"><b>Biennials </b>or (monocarpic) perennials, 50–300 cm;</span> <span class="statement" id="st-d0_s1" data-properties="herbage architecture or shape">herbage not spiny.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem architecture;branch orientation"><b>Stems </b>erect, openly branched, branches ascending.</span> <span class="statement" id="st-d0_s3" data-properties=""><b>Leaves </b>basal and cauline;</span> <span class="statement" id="st-d0_s4" data-properties="">long-petiolate;</span> <span class="statement" id="st-d0_s5" data-properties="leaf position;leaf position;leaf architecture;leaf size">gradually smaller distally;</span> <span class="statement" id="st-d0_s6" data-properties="blade margin architecture or shape;blade margin architecture or shape;face pubescence;face pubescence">blade margins entire or dentate (pinnately lobed or dissected), faces abaxially resin-gland-dotted, adaxially often tomentose.</span> <span class="statement" id="st-d0_s7" data-properties="head architecture or shape;array architecture;array architecture"><b>Heads </b>discoid, in leafy-bracted racemiform to paniculiform or corymbiform arrays.</span> <span class="statement" id="st-d0_s8" data-properties="involucre shape">(Peduncles 0 or 1–9 cm.) Involucres spheric to ovoid.</span> <span class="statement" id="st-d0_s9" data-properties="phyllary quantity;series quantity;outer and mid phyllary arrangement or course or shape;base fixation or orientation;margin architecture or shape;apex arrangement;apex architecture or shape;apex architecture;inner phyllary arrangement or course or shape;inner phyllary orientation;inner phyllary orientation;inner phyllary architecture"><b>Phyllaries </b>many in 9–17 series, outer and mid narrowly linear, bases appressed, margins entire, apices stiffly radiating, hooked-spiny tipped, inner linear, ascending or erect, straight-tipped.</span> <span class="statement" id="st-d0_s10" data-properties="receptacle prominence or shape;receptacle architecture;scale shape"><b>Receptacles </b>± flat, epaleate, bearing subulate scales.</span> <span class="statement" id="st-d0_s11" data-properties="floret atypical quantity;floret quantity"><b>Florets </b>(5–) 20–40+;</span> <span class="statement" id="st-d0_s12" data-properties="corolla coloration;corolla pubescence;corolla pubescence;tube shape;throat shape;lobe shape;lobe variability">corollas pink to ± purple, glabrous or glandular-puberulent, tubes elongate, throats campanulate, lobes narrowly triangular, ± equal;</span> <span class="statement" id="st-d0_s13" data-properties="anther base shape;apical appendage shape;apical appendage shape">anther bases tailed, apical appendages ovate, obtuse to acute;</span> <span class="statement" id="st-d0_s14" data-properties="portion fusion;portion relief;portion fusion;portion shape;portion shape;portion shape">style-branches: fused portions distally hairy-ringed, distinct portions oblong, acute or obtuse.</span> <span class="statement" id="st-d0_s15" data-properties="cypsela shape;cypsela shape;cypsela pubescence or relief;cypsela architecture or shape;cypsela pubescence;attachment scar position"><b>Cypselae </b>obovoid, ± compressed, rough or ribbed, glabrous, attachment scars basal;</span> <span class="statement" id="st-d0_s16" data-properties="bristle quantity;series quantity">pappi falling, of many bristles in 2–4 series.</span> <span class="statement" id="st-d0_s17" data-properties="pappus life cycle;x chromosome quantity">x = 18.</span><!--

-->{{Treatment/Body
|distribution=Eurasia;n Africa;widely  worldwide
|introduced=true
|discussion=<p>Species 10 (3 in the flora).</p><!--
--><p>At maturity the dry heads of Arctium species are readily caducous with the enclosed cypselae, and the hooked phyllary tips cling easily to fur or fabrics. Animal dispersal is a major factor in the spread of burdock species across North America. The burs are a major problem when they become entangled in the wool of sheep and fur of dogs and other animals.</p><!--
--><p>Published chromosome reports for Arctium other than n = 18 are probably in error because of difficulty in interpretation of somatic chromosomes (R. J. Moore and C. Frankton 1974).</p>
|tables=
|references={{Treatment/Reference
|id=arenes1950a
|text=Arènes, J. 1950. Monographie du genre Arctium L. Bull. Jard. Bot. État Bruxelles 29: 67–156.
}}{{Treatment/Reference
|id=duistermaat1996a
|text=Duistermaat, H. 1996. Monograph of Arctium L. (Asteraceae). Gorteria, suppl. 3: 1–143.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Heads usually sessile to short-pedunculate in racemiform or paniculiform clusters.
|[[Arctium minus|Arctium minus]]
|-id=key-0-1
|1
|Heads usually long-pedunculate in corymbiform clusters
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Involucre 2.5–4 cm diam.; phyllary apices glabrous or loosely cobwebby; corollas glabrous
|[[Arctium lappa|Arctium lappa]]
|-id=key-0-2
|2
|Involucre 1.5–2.5 mm diam.; phyllary apices densely cobwebby; corollas minutely glandular-puberulent
|[[Arctium tomentosum|Arctium tomentosum]]
|}
</div></div><!--

-->{{#Taxon:
name=Arctium
|author=David J. Keil
|authority=Linnaeus
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=Eurasia;n Africa;widely  worldwide
|introduced=true
|reference=arenes1950a;duistermaat1996a
|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/V19-20-21/V19_183.xml
|tribe=Asteraceae tribe Cardueae
|genus=Arctium
|anther base shape=tailed
|apex architecture=tipped
|apex architecture or shape=hooked-spiny
|apex arrangement=radiating
|apical appendage shape=obtuse;acute
|array architecture=racemiform;paniculiform or corymbiform
|attachment scar position=basal
|base fixation or orientation=appressed
|blade margin architecture or shape=dentate;entire
|branch orientation=ascending
|bristle quantity=many
|corolla coloration=pink;more or less purple
|corolla pubescence=glandular-puberulent;glabrous
|cypsela architecture or shape=ribbed
|cypsela pubescence=glabrous
|cypsela pubescence or relief=rough
|cypsela shape=compressed;obovoid
|face pubescence=tomentose;resin-gland-dotted
|floret atypical quantity=5;20
|floret quantity=20;40
|head architecture or shape=discoid
|herbage architecture or shape=not spiny
|inner phyllary architecture=straight-tipped
|inner phyllary arrangement or course or shape=linear
|inner phyllary orientation=erect;ascending
|involucre shape=spheric;ovoid
|leaf architecture=long-petiolate
|leaf position=cauline;basal
|leaf size=smaller
|lobe shape=triangular
|lobe variability=equal
|margin architecture or shape=entire
|outer and mid phyllary arrangement or course or shape=linear
|pappus life cycle=falling
|phyllary quantity=many
|portion fusion=distinct;fused
|portion relief=hairy-ringed
|portion shape=obtuse;acute;oblong
|receptacle architecture=epaleate
|receptacle prominence or shape=flat
|scale shape=subulate
|series quantity=2;4
|stem architecture=branched
|stem orientation=erect
|throat shape=campanulate
|tube shape=elongate
|whole-organism duration=perennial;biennial
|whole-organism some measurement=50cm;300cm
|x chromosome quantity=18
}}<!--

-->[[Category:Treatment]][[Category:Asteraceae tribe Cardueae]]