View source for Senecio jacobaea

{{Treatment/ID
|accepted_name=Senecio jacobaea
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 870. 1753
|year=1753
}}
|common_names=Tansy ragwort;stinking Willie
|special_status={{Treatment/ID/Special_status
|code=I
|label=Introduced
}}{{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Jacobaea vulgaris
|authority=Gaertner
|rank=species
}}
|hierarchy=Asteraceae;Asteraceae tribe Senecioneae;Senecio;Senecio jacobaea
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Senecioneae]]</div><div class="higher-taxon"><small>genus</small>[[Senecio]]</div><div class="higher-taxon"><small>species</small>[[Senecio jacobaea]]</div></div>
|volume=Volume 20
|mention_page=page 546, 570
|treatment_page=page 568
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> 20–80(–100) cm (taprooted or branched caudices surmounting taproots). <b>Herbage</b> sparsely and unevenly tomentose, glabrescent except in leaf axils and among heads. <b>Stems</b> (often purplish-tinged) usually single, sometimes loosely clustered. <b>Leaves</b> ± evenly distributed (basal often withering before flowering); petiolate (sometimes obscurely); blades ovate to broadly ovate (usually 1–3-pinnate, lobes mostly obovate to spatulate), (4–)7–20(–30) × (1–)2–5(–12) cm, bases usually tapered, ultimate margins dentate (distal leaves similar, smaller). <b>Heads</b> (10–)20–60+ in corymbiform arrays. <b>Calyculi</b> of 2–6 (inconspicuous) bractlets (less than 2 mm). <b>Phyllaries</b> ± 13, 3–4(–5) mm, tips black or greenish. <b>Ray</b> florets ± 13; corolla laminae 8–12 mm. <b>Cypselae</b> all sparsely hairy or ray cypselae glabrous. <b>2n</b> = 40.</span><!--

-->{{Treatment/Body
|phenology=Flowering spring–early summer(–fall).
|habitat=Disturbed sites, pastures, roadsides, and waste grounds
|elevation=0–1500 m
|distribution=St. Pierre and Miquelon;B.C.;N.B.;Nfld. and Labr. (Nfld.);N.S.;Ont.;P.E.I.;Que.;Calif.;Idaho;Ill.;Maine;Mass.;Mich.;Mont.;N.J.;N.Y.;Oreg.;Pa.;Wash.;Europe.
|introduced=true
|discussion=<p><i>Senecio jacobaea</i> is a weed introduced from Europe and now well established in places of cool, damp summers. It is toxic to livestock and legally noxious in most states and provinces where it occurs.</p><!--
--><p>The Russian botanist E. Wiebe (2000) resuscitated Jacobaea for plants that are treated here as <i>Senecio jacobaea</i>, <i>S. erucifolius</i>, and <i>S. cannabifolius</i>. Phylogenetic studies may confirm the utility of recognizing Jacobaea as a distinct genus; to do so here would be premature.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Senecio jacobaea
|authority=Linnaeus
|rank=species
|parent rank=genus
|synonyms=Jacobaea vulgaris
|basionyms=
|family=Asteraceae
|phenology=Flowering spring–early summer(–fall).
|habitat=Disturbed sites, pastures, roadsides, and waste grounds
|elevation=0–1500 m
|distribution=St. Pierre and Miquelon;B.C.;N.B.;Nfld. and Labr. (Nfld.);N.S.;Ont.;P.E.I.;Que.;Calif.;Idaho;Ill.;Maine;Mass.;Mich.;Mont.;N.J.;N.Y.;Oreg.;Pa.;Wash.;Europe.
|introduced=true
|reference=None
|publication title=Sp. Pl.
|publication year=1753
|special status=Introduced;Illustrated
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V20_1279.xml
|tribe=Asteraceae tribe Senecioneae
|genus=Senecio
|species=Senecio jacobaea
}}<!--

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