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-undefined" data-properties=""><b>Biennials </b>or (monocarpic) perennials, 50–300 cm; herbage not spiny. <b>Stems</b> erect, openly branched, branches ascending. <b>Leaves</b> basal and cauline; long-petiolate; gradually smaller distally; blade margins entire or dentate (pinnately lobed or dissected), faces abaxially resin-gland-dotted, adaxially often tomentose. <b>Heads</b> discoid, in leafy-bracted racemiform to paniculiform or corymbiform arrays. (Peduncles 0 or 1–9 cm.) Involucres spheric to ovoid. <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. <b>Receptacles</b> ± flat, epaleate, bearing subulate scales. <b>Florets</b> (5–)20–40+; corollas pink to ± purple, glabrous or glandular-puberulent, tubes elongate, throats campanulate, lobes narrowly triangular, ± equal; anther bases tailed, apical appendages ovate, obtuse to acute; style branches: fused portions distally hairy-ringed, distinct portions oblong, acute or obtuse. <b>Cypselae</b> obovoid, ± compressed, rough or ribbed, glabrous, attachment scars basal; pappi falling, of many bristles in 2–4 series. <b>x</b> = 18.</span><!--

-->{{Treatment/Body
|distribution=Eurasia;n Africa;widely introduced worldwide.
|discussion=<p>Species 10 (3 in the flora).</p><!--
--><p>At maturity the dry heads of <i>Arctium</i> 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 <i>Arctium</i> 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 introduced worldwide.
|introduced=true
|reference=arenes1950a;duistermaat1996a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;1754
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V19-20-21/V19_183.xml
|tribe=Asteraceae tribe Cardueae
|genus=Arctium
}}<!--

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