View source for Cirsium horridulum

{{Treatment/ID
|accepted_name=Cirsium horridulum
|accepted_authority=Michaux
|publications={{Treatment/Publication
|title=Fl. Bor.-Amer.
|place=2: 90. 1803
|year=1803
}}
|common_names=Bristly or horrid or yellow or bull thistle
|special_status={{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Cardueae;Cirsium;Cirsium horridulum
|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>[[Cirsium]]</div><div class="higher-taxon"><small>species</small>[[Cirsium horridulum]]</div></div>
|volume=Volume 19
|mention_page=page 99, 113
|treatment_page=page 114
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Biennials </b>or perennials, (± fleshy), 15–250 cm; stout taproots and a fascicle of fleshy lateral roots, often perennating by root sprouts. <b>Stems</b> 1–several, usually erect, often stout, glabrous to densely tomentose; branches 0–many, spreading to ascending, short, stout. <b>Leaves</b>: blades linear to oblanceolate or oblong-elliptic, 10–40 × 2–10 cm, unlobed and spiny-dentate to deeply pinnatifid, lobes spiny-dentate or coarsely lobed, main spines stout, 5–30 mm, abaxial faces subglabrous to loosely tomentose, adaxial glabrous to ± densely villous with septate trichomes; basal present at flowering, spiny winged-petiolate, bases often tapered; principal cauline sessile, well distributed, often not much reduced distally, bases often ± auriculate-clasping; distal cauline often spinier than the proximal. <b>Heads</b> 1–20 in subcapitate to corymbiform arrays (each closely subtended by an involucre-like ring of spiny-margined bracts). <b>Peduncles</b> 0–5 cm. <b>Involucres</b> hemispheric to campanulate, 3–5 × 3–8 cm. <b>Phyllaries</b> in 5–9 series, subequal to imbricate, light green to stramineous, lanceolate to linear, distally often with reddish margins, abaxial faces without glutinous ridge, often ± thinly tomentose, often scabridulous in submarginal bands; outer and middle appressed-ascending, bodies usually reddish-tinged, margins setulose-ciliolate, apices acuminate, spines 1–2 mm, weak; apices of inner straight, flat. <b>Corollas</b> white to yellow, pink, purple, or red, 30–47 mm, tubes 11–30 mm, throats 6–10 mm, lobes 7–10 mm; style tips 3–5 mm. <b>Cypselae</b> straw-colored to tan, 4–6 mm, apical collars weakly differentiated; pappi 25–35 mm. <b>2n</b> = 32, 33, 34, 35.</span><!--

-->{{Treatment/Body
|distribution=Ala.;Ark.;Conn.;Del.;Fla.;Ga.;La.;Maine;Mass.;Md.;Miss.;N.C.;N.H.;N.J.;N.Y.;Okla.;Pa.;R.I.;S.C.;Tenn.;Tex.;Va.;Mexico.
|discussion=<p>Varieties 4 (3 in the flora).</p><!--
--><p>Although several variants have been given taxonomic recognition as species, these seem at most races. Flower color varies greatly, sometimes within populations and sometimes on a populational or regional basis. Herbarium specimens are sometimes difficult to assign to variety.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems densely tomentose; involucres ± densely tomentose
|[[Cirsium horridulum var. horridulum|Cirsium horridulum var. horridulum]]
|-id=key-0-1
|1
|Stems glabrous or sparsely tomentose; involucres glabrous
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Leaves shallowly to deeply pinnatifid, main spines 10–30 mm
|[[Cirsium horridulum var. megacanthum|Cirsium horridulum var. megacanthum]]
|-id=key-0-2
|2
|Leaves spinose-dentate to shallowly pinnatifid, main spines mostly 5–10 mm
|[[Cirsium horridulum var. vittatum|Cirsium horridulum var. vittatum]]
|}
</div></div><!--

-->{{#Taxon:
name=Cirsium horridulum
|authority=Michaux
|rank=species
|parent rank=genus
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=Ala.;Ark.;Conn.;Del.;Fla.;Ga.;La.;Maine;Mass.;Md.;Miss.;N.C.;N.H.;N.J.;N.Y.;Okla.;Pa.;R.I.;S.C.;Tenn.;Tex.;Va.;Mexico.
|reference=None
|publication title=Fl. Bor.-Amer.
|publication year=1803
|special status=Illustrated
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V19_62.xml
|tribe=Asteraceae tribe Cardueae
|genus=Cirsium
|species=Cirsium horridulum
}}<!--

-->

[[Category:Treatment]]
[[Category:Cirsium]]
[[Category:Revised Since Print]]