View source for Helianthus pauciflorus

{{Short description|Species of sunflower}}
{{Speciesbox
| image = Helianthus pauciflorus (H. rigidus) (5020605591).jpg
| status = LC
| status_system = IUCN3.1
| status_ref =
| status2 = {{TNCStatus}}
| status2_system = TNC
| status2_ref = 
| genus = Helianthus
| species = pauciflorus
| authority = [[Nutt.]]
| synonyms_ref = <ref name=h>{{ThePlantList |id=gcc-30040 |taxon=Helianthus pauciflorus}}</ref>
| synonyms =
* ''Harpalium rigidum'' <small>[[Cass.]]</small>
* ''Helianthus rigidus'' <small>(Cass.) [[Desf.]]</small>
* ''Helianthus subrhomboideus'' <small>[[Rydb.]], syn of subsp. subrhomboideus</small>
}}

'''''Helianthus pauciflorus''''', called the '''stiff sunflower''', is a North American plant species in the family [[Asteraceae]]. It is widespread across the [[Great Plains]], the [[Rocky Mountains]], and the [[Great Lakes region]], and naturalized in scattered locations in the eastern United States and in much of southern Canada (from [[Alberta]] to [[Nova Scotia]]).<ref>{{BONAP|ref |genus=Helianthus |species=pauciflorus}}</ref>

Stiff sunflower is a [[perennial]] [[herbaceous plant|herb]] {{cvt|50|-|200|cm|ftin|0}} tall, spreading by means of underground [[rhizomes]]. Most of the leaves are attached near the bottom of the stem. One plant can produces 1-10 [[flower heads]], each head with 10-20 yellow [[ray florets]] surrounding at least 75 red or (less often) yellow [[disc floret]]s.<ref name="FNA">{{eFloras|1|250066894|Helianthus pauciflorus |tribe=Heliantheae |first=Edward E. |last=Schilling}}</ref>

Hybrids between ''H. pauciflorus'' and ''[[Helianthus tuberosus|H. tuberosus]]'' (Jerusalem artichoke) are known as [[Helianthus × laetiflorus|''H.'' × ''laetiflorus'']]. The name ''H. laetiflorus'' has also been used as a synonym of ''H. pauciflorus''.<ref>{{eFloras|1|250068450|Helianthus × laetiflorus |tribe=Heliantheae |first=Edward E. |last=Schilling}}</ref>

; Subspecies<ref name=h/>
* ''Helianthus pauciflorus'' subsp. ''pauciflorus'': {{cvt|80|-|200|cm|ftin|0}} tall; leaves [[alternate leaf|alternate]] near the end of the stem, {{cvt|8|-|27|cm|in|frac=4}} long, with tips [[acuminate]] (tapered to a point).<ref name="FNA" />
* ''Helianthus pauciflorus'' subsp. ''subrhomboideus'' <small>([[Rydb.]]) [[Otmar Spring|O.Spring]] & [[Edward E. Schilling|E.E.Schill.]]</small>:<ref>{{IPNI |id=1070491-2 |taxon=Helianthus pauciflorus subsp. subrhomboideus |authority=(Rydb.) O.Spring & E.E.Schill.}}</ref><ref>{{cite journal |first1=Otmar |last1=Spring |first2=Edward E. |last2=Schilling |title=The origin of Helianthus × multiflorus and H. × laetiflorus (Asteraceae) |journal=Biochemical Systematics and Ecology |volume=18 |issue=1 |date=1990 |pages=19–23 |doi=10.1016/0305-1978(90)90027-D|bibcode=1990BioSE..18...19S }}</ref><!-- for names of authors --> {{cvt|50|-|120|cm|ftin|0}} tall; leaves [[opposite leaf|opposite]], {{cvt|5|-|12|cm|in|0}} long, with acute or obtuse tips.<ref name="FNA" />

==References==
{{Reflist}}
* {{cite book | author=Pink, A. | url=https://www.gutenberg.org/ebooks/11892|title=Gardening for the Million| year=2004 | publisher=[[Project Gutenberg]] Literary Archive Foundation}}

==External links==
* {{Illinois Wildflowers|prairie/plantx/pr_sunflowerx |link=1}}
* {{Kansas Wildflowers|164 |link=1}}
* {{Michigan Flora |id=356 |link=1}}
* {{Minnesota Wildflowers|flower/stiff-sunflower |link=1}}
* {{Flora of Wisconsin|3820 |link=1}}
* {{NPIN |link=1}}

{{Taxonbar|from=Q4117073}}

[[Category:Helianthus|pauciflorus]]
[[Category:Plants described in 1818]]
[[Category:Flora of Northern America]]