View source for Cirsium scariosum var. americanum

{{Treatment/ID
|accepted_name=Cirsium scariosum var. americanum
|accepted_authority=(A. Gray) D. J. Keil
|publications={{Treatment/Publication
|title=Sida
|place=21: 215. 2004
|year=2004
}}
|common_names=Dinnerplate or sessile or stemless thistle
|special_status={{Treatment/ID/Special_status
|code=F
|label=Illustrated
}}
|basionyms={{Treatment/ID/Basionym
|name=Cirsium acaule var. americanum
|authority=A. Gray
|rank=variety
|publication_title=Proc. Acad. Nat. Sci. Philadelphia
|publication_place=15: 68. 1864
}}
|synonyms={{Treatment/ID/Synonym
|name=Cirsium acaulescens
|authority=(A. Gray) K. Schumann
|rank=species
}} {{Treatment/ID/Synonym
|name=Cirsium americanum
|authority=(A. Gray) K. Schumann
|rank=species
}} {{Treatment/ID/Synonym
|name=Cirsium coloradense subsp. acaulescens
|authority=(A. Gray) Petrak
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Cirsium coloradense subsp. longissimum
|authority=(A. Heller) Petrak
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Cirsium drummondii var. acaulescens
|authority=(A. Gray) J. F. Macbride
|rank=variety
}} {{Treatment/ID/Synonym
|name=Cirsium drummondii subsp. latisquamum
|authority=Petrak
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Cirsium drummondii var. oregonense
|authority=Petrak
|rank=variety
}} {{Treatment/ID/Synonym
|name=Cirsium drummondii subsp. vexans
|authority=Petrak
|rank=subspecies
}} {{Treatment/ID/Synonym
|name=Cirsium tioganum
|authority=
|rank=species
}}
|hierarchy=Asteraceae;Asteraceae tribe Cardueae;Cirsium;Cirsium scariosum;Cirsium scariosum var. americanum
|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 scariosum]]</div><div class="higher-taxon"><small>variety</small>[[Cirsium scariosum var. americanum]]</div></div>
|volume=Volume 19
|mention_page=page 155
|treatment_page=page 156
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>usually acaulescent or nearly so (with dense rosettes of leaves and cluster of sessile or subsessile heads), less commonly caulescent and to 45 cm. <b>Stems</b> absent or short, stout, fleshy, usually unbranched, very leafy, villous or tomentose with septate trichomes. <b>Leaves</b>: blades linear to oblong, oblanceolate, or narrowly elliptic, pinnately lobed or often unlobed, longer spines slender or stout, usually 1 cm or less, sometimes unpigmented proximally or tinged pink or purplish, abaxial faces gray-tomentose with fine, non-septate trichomes and/or villous with septate trichomes, adaxial glabrous or thinly villous with septate trichomes. <b>Heads</b> 1–many, sessile or subsessile, crowded. <b>Involucres</b> 1.5–3 cm. <b>Phyllaries</b>: outer and mid lanceolate to ovate, spines slender to stout, 1–12 mm; apices of inner acuminate and entire or abruptly expanded into scarious, erose-toothed appendage. <b>Corollas</b> white or pink-tinged (rarely purple), 22–30 mm, tubes 11.5–16.5 mm, throats 5–10.5 mm, lobes 5–6.5 mm; style tips 3.5–6.5 mm. <b>Cypselae</b> 4.5–6 mm; pappi 20–25 mm. <b>2n</b> = 34 (as <i>C. foliosum</i>).</span><!--

-->{{Treatment/Body
|phenology=Flowering summer (Jun–Aug).
|habitat=Seasonally damp, sometimes saline soil in meadows, grasslands, open forests, sagebrush scrub
|elevation=1100–3800 m
|distribution=Calif.;Colo.;Idaho;Nev.;Oreg.;Utah;Wyo.;Mexico (Baja California).
|discussion=<p>Variety americanum is a variable taxon widely distributed in mountains and valleys of the western United States from the eastern slope of the Cascades and Sierra <i>Nevada</i> across the northern Great Basin to the central Rocky Mountains. Within some populations dominated by acaulescent forms, occasional short, caulescent individuals or even taller plants may occur. These approach <i></i>var.<i> coloradense</i> in the Colorado Rockies and resemble <i></i>var.<i> scariosum</i> in the valleys of Oregon. Short caulescent individuals within populations of <i></i>var.<i> coloradense</i> and <i></i>var.<i> scariosum</i> approach <i></i>var.<i> americanum</i>. Although the extremes are strikingly different, the genetic differences are apparently slight. Acaulescent individuals from the San Francisco Peaks and White Mountains of Arizona are treated here as <i></i>var.<i> coloradense</i>. In the mountains of Colorado putative hybrids have been documented between <i>Cirsium scariosum </i>var.<i> americanum</i> and <i>C. canescens</i> and between <i>C. scariosum </i>var.<i> americanum</i> and <i>C. undulatum</i>.</p>
|tables=
|references=
}}<!--

--><!--

-->{{#Taxon:
name=Cirsium scariosum var. americanum
|authority=(A. Gray) D. J. Keil
|rank=variety
|parent rank=species
|synonyms=Cirsium acaulescens;Cirsium americanum;Cirsium coloradense subsp. acaulescens;Cirsium coloradense subsp. longissimum;Cirsium drummondii var. acaulescens;Cirsium drummondii subsp. latisquamum;Cirsium drummondii var. oregonense;Cirsium drummondii subsp. vexans;Cirsium tioganum
|basionyms=Cirsium acaule var. americanum
|family=Asteraceae
|phenology=Flowering summer (Jun–Aug).
|habitat=Seasonally damp, sometimes saline soil in meadows, grasslands, open forests, sagebrush scrub
|elevation=1100–3800 m
|distribution=Calif.;Colo.;Idaho;Nev.;Oreg.;Utah;Wyo.;Mexico (Baja California).
|reference=None
|publication title=Sida
|publication year=2004
|special status=Illustrated
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V19_153.xml
|tribe=Asteraceae tribe Cardueae
|genus=Cirsium
|species=Cirsium scariosum
|variety=Cirsium scariosum var. americanum
}}<!--

-->[[Category:Treatment]][[Category:Cirsium scariosum]]