View source for Helianthus grosseserratus

{{short description|Species of plant}}
{{Speciesbox
|image = Helianthus grosseserratus 2.jpg
|status = LC
|status_system = IUCN3.1
|status_ref =
|genus = Helianthus
|species = grosseserratus
|authority = [[Martin Martens|M.Martens]]<ref name="USDA">{{PLANTS |symbol=HEGR4 |taxon=Helianthus grosseserratus |accessdate=2010-10-11}}
</ref>
|synonyms_ref = <ref>{{ThePlantList |id=gcc-122800 |taxon=Helianthus grosseserratus}}</ref>
|synonyms = *''Helianthus instabilis'' <small>E.Watson</small>
}}

'''Helianthus grosseserratus''', commonly known as '''sawtooth sunflower''' or '''thick-tooth sunflower''',<ref name="ars">{{GRIN | accessdate=2008-07-16}}</ref> is a perennial [[Helianthus|sunflower]] in the family Asteraceae, with a large flowering head (inflorescence).

The plant may reach 3–7 feet (91–366&nbsp;cm) in height with instances to 12 and is found along streams, damp prairies and roadsides in the eastern and central parts of Canada and the United States, primarily in the northern [[Great Plains]] and [[Great Lakes Region]], with additional populations as far as [[Maine]], [[Georgia (U.S. state)|Georgia]], and [[Texas]].<ref name="ars"/><ref>{{BONAP|ref |genus=Helianthus |species=grosseserratus}}</ref> It prefers full sun and moist, fertile loamy soil with high organic content.<ref name="IL">{{Illinois Wildflowers|prairie/plantx/swt_sunflowerx|Helianthus grosseserratus |access-date=2008-07-16}}</ref>

The [[leaf shape|lanceolate]] leaves are glossy, simple and alternate and may reach 4 to 12&nbsp;inches (10–30&nbsp;cm) long and from 1 to 4&nbsp;inches (2–10&nbsp;cm) wide. The leaves have large teeth along the edges (hence the name, ''sawtooth'') to occasionally nearly entire and the tips are pointed.<ref name=w>{{eFloras|1|242416631|Helianthus grosseserratus |tribe=Heliantheae |first=Edward E. |last=Schilling}}</ref>

The [[Head (botany)|head]] (formally composite flower) is 3 to 4&nbsp;inches (7–10&nbsp;cm) wide with golden-yellow disk flowers that bloom in summer and autumn. The 10-20 yellow ray florets are about 1.5&nbsp;inches (3.81&nbsp;cm) long. The fruit is a single [[achene]] within a husk.<ref name=w/>

Various insects, birds and mammals (including cattle) feed on either the plant or its seeds.<ref name="IL"/><ref name="KS">{{Kansas Wildflowers|162|Sawtooth sunflower}}</ref>

Native Americans used to treat burns with a poultice made from the flowers.<ref name="KS"/>

==See also==
*[[Jerusalem artichoke]]

==References==
{{Reflist}}

==External links==
*[http://www.tropicos.org/ImageFullView.aspx?imageid=100385735 Photo of herbarium specimen at Missouri Botanical Garden, collected in Wisconsin in 2014]
*[http://www.tropicos.org/Image/100170712 Photo of base of stem, showing formation of roots and rhizomes]

{{Taxonbar|from=Q5704861}}

[[Category:Helianthus|grosseserratus]]
[[Category:Flora of Northern America]]
[[Category:Plants described in 1839]]