View source for Centaurea nigrescens

{{Treatment/ID
|accepted_name=Centaurea nigrescens
|accepted_authority=Willdenow
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=3: 2288. 1803
|year=1803
}}
|common_names=Tyrol or short-fringed or Vochin knapweed;centaurée noirâtre
|special_status={{Treatment/ID/Special_status
|code=I
|label=Introduced
}}
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Centaurea dubia subsp. nigrescens
|authority=(Willdenow) Hayek
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Centaurea dubia subsp. vochinensis
|authority=(Bernhardi ex Reichenbach) Hayek
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Centaurea jacea subsp. nigrescens
|authority=(Willdenow) Celakovsky
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Centaurea transalpina
|authority=Bernhardi ex Reichenbach
|rank=species
}} {{Treatment/ID/Synonym
|name=Centaurea vochinensis
|authority=
|rank=species
}}
|hierarchy=Asteraceae;Asteraceae tribe Cardueae;Centaurea;Centaurea nigrescens
|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>[[Centaurea]]</div><div class="higher-taxon"><small>species</small>[[Centaurea nigrescens]]</div></div>
|volume=Volume 19
|mention_page=page 184, 186, 187, 189
|treatment_page=page 188
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> 30–150 cm. <b>Stems</b> 1–few, erect or ascending, openly branched distally, villous to scabrous with septate hairs and loosely tomentose, ± glabrate. <b>Leaves</b>: basal and proximal cauline, petiolate, blades oblanceolate or elliptic, 5–25 cm, margins entire or shallowly dentate to irregularly pinnately lobed; distal cauline sessile, not decurrent, blades linear to lanceolate, gradually smaller, entire or dentate. <b>Heads</b> radiant or discoid, in few-headed corymbiform arrays, borne on leafy-bracted peduncles. <b>Involucres</b> 15–18 mm, subcylindric to ovoid or campanulate, usually longer than wide, even when pressed. <b>Principal</b> phyllaries: bodies lanceolate to ovate, loosely tomentose or glabrous, usually not fully covered by narrow appendages, these erect, overlapping, dark brown to black, flat, margins pectinately dissected into 6–8 pairs of wiry lobes. <b>Inner</b> phyllaries: tips truncate, irregularly dentate or lobed. <b>Florets</b> 40–100+, all fertile or peripheral sterile; corollas purple (rarely white), those of sterile florets ± expanded and exceeding corollas of fertile florets, those of fertile florets 15–18 mm. <b>Cypselae</b> tan, 2.5–3 mm, finely hairy; pappi 0 or of many unequal, sometimes caducous bristles 0.5–1 mm. <b>2n</b> = 22 (Hungary), 44 (Hungary; Italy).</span><!--

-->{{Treatment/Body
|phenology=Flowering summer–fall (Jun–Oct).
|habitat=Roadsides, fields, waste areas
|elevation=0–1000 m
|distribution=B.C.;Ont.;Que.;Calif.;Conn.;Del.;Fla.;Ill.;Ind.;Mass.;Mo.;Mont.;N.H.;N.J.;N.Y.;Ohio;Oreg.;Pa.;R.I.;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Europe.
|introduced=true
|discussion=<p>Tyrol knapweed is considered to be a noxious weed in Washington and Oregon.</p><!--
--><p>In recent years there has been much controversy regarding the name(s) to be applied to the North American Tyrol knapweeds. The names <i>Centaurea</i> vochinensis, <i>C. nigrescens</i>, and C. dubia have all been used in twentieth-century North American floras, and J. T. Kartesz and C. A. Meacham (1999) have accepted C. transalpina as well. R. J. Moore (1972) tentatively accepted two species, <i>C. nigrescens</i> and C. dubia, placing C. transalpina and C. vochinensis as synonyms through application beneath both species. Moore discussed the considerable similarities and practical difficulties of differentiating the taxa. H. A. Gleason and A. Cronquist (1991) recognized C. dubia as including <i>C. nigrescens</i> and C. vochinensis. E. G. Voss (1972–1996, vol. 3) recognized <i>C. nigrescens</i> as including C. dubia and C. vochinensis. Kartesz and Meacham accept <i>C. nigrescens</i> as a species, including C. vochinensis; they also accept C. transalpina with C. dubia as a synonym. In our investigation of the North American Tyrol knapweeds we have not been able to distinguish more than one (admittedly variable) entity. At the species level the correct name for this taxon is <i>Centaurea nigrescens</i>.</p><!--
--><p><i>Centaurea</i> dubia Suter, sometimes applied to plants that belong here, is not a valid name.</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Centaurea nigrescens
|authority=Willdenow
|rank=species
|parent rank=genus
|synonyms=Centaurea dubia subsp. nigrescens;Centaurea dubia subsp. vochinensis;Centaurea jacea subsp. nigrescens;Centaurea transalpina;Centaurea vochinensis
|basionyms=
|family=Asteraceae
|phenology=Flowering summer–fall (Jun–Oct).
|habitat=Roadsides, fields, waste areas
|elevation=0–1000 m
|distribution=B.C.;Ont.;Que.;Calif.;Conn.;Del.;Fla.;Ill.;Ind.;Mass.;Mo.;Mont.;N.H.;N.J.;N.Y.;Ohio;Oreg.;Pa.;R.I.;Vt.;Va.;Wash.;W.Va.;Wis.;Wyo.;Europe.
|introduced=true
|reference=None
|publication title=Sp. Pl.
|publication year=1803
|special status=Introduced
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-data-curation.git/src/bb6b7e3a7de7d3b7888a1ad48c7fd8f5c722d8d6/coarse_grained_fna_xml/V19-20-21/V19_214.xml
|tribe=Asteraceae tribe Cardueae
|genus=Centaurea
|species=Centaurea nigrescens
}}<!--

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