View source for Helianthus giganteus

{{Treatment/ID
|accepted_name=Helianthus giganteus
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 905. 1753
|year=1753
}}
|common_names=Giant or tall sunflower;hélianthe géant
|basionyms=
|synonyms={{Treatment/ID/Synonym
|name=Helianthus alienus
|authority=E. Watson
}} {{Treatment/ID/Synonym
|name=Helianthus validus
|authority=E. Watson
}}
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Helianthinae;Helianthus;Helianthus giganteus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Heliantheae]]</div><div class="higher-taxon"><small>subtribe</small>[[Asteraceae (tribe Heliantheae) subtribe Helianthinae]]</div><div class="higher-taxon"><small>genus</small>[[Helianthus]]</div><div class="higher-taxon"><small>species</small>[[Helianthus giganteus]]</div></div>
|volume=Volume 21
|mention_page=page 147, 163
|treatment_page=page 165
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> 100–400 cm (rhizomatous). <b>Stems</b> (usually reddish) erect, hairy. <b>Leaves</b> cauline; mostly alternate; petioles 0–1.2 cm (ciliate); blades (3-nerved from bases) lanceolate to lance-ovate, 7–20 × 1.2–3.5 cm, bases cuneate, margins serrulate to subentire (± flat), abaxial faces scabrous or ± hirsute, sometimes gland-dotted. <b>Heads</b> 1–12. <b>Peduncles</b> 8–12 mm. <b>Involucres</b> hemispheric, 10–24 mm diam. <b>Phyllaries</b> 20–25 (loose or spreading), linear, 8–15 × 1.2–2 mm, (margins usually ciliate) apices acute to attenuate, abaxial faces sparsely strigose, not gland-dotted. <b>Paleae</b> 7–9 mm, entire or ± 3-toothed (apices acute, hairy). <b>Ray</b> florets 12–20; laminae (often pale yellow) 15–25 mm (abaxial faces not gland-dotted). <b>Disc</b> florets 60+; corollas 5–6 mm, lobes yellow; anthers dark brown or black, appendages dark. <b>Cypselae</b> 3–4 mm, glabrate; pappi of 2 aristate scales 2.4–3 mm. <b>2n</b> = 34.</span><!--

-->{{Treatment/Body
|phenology=Flowering late summer–fall.
|habitat=Usually wet, open sites
|elevation=10–600+ m
|distribution=N.B.;Nfld. and Labr. (Nfld.);N.S.;Ont.;Que.;Conn.;Del.;D.C.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;N.J.;N.Y.;N.C.;Ohio;Pa.;S.C.;Tenn.;Vt.;Va.;W.Va.;Wis.
|discussion=<p><i>Helianthus giganteus</i> was probably introduced in Newfoundland. It intergrades with <i>H. nuttallii</i> and <i>H. grosseserratus</i>; it is distinctive in its hairy, reddish-colored stems, dark anther appendages, and prominent setae on the petioles. The natural hybrid of <i>H. giganteus</i> with <i>H. grosseserratus</i> has been called H. luxurians E. Watson (R. W. Long 1954). Hybrids of <i>H. giganteus</i> with <i>H. divaricatus</i> have been referred to as H. ambiguus (Torrey & A. Gray) Britton and H. ×divariserratus R. W. Long (Long 1954).</p>
|tables=
|references=
}}<!--

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-->{{#Taxon:
name=Helianthus giganteus
|author=
|authority=Linnaeus
|rank=species
|parent rank=genus
|synonyms=Helianthus alienus;Helianthus validus
|basionyms=
|family=Asteraceae
|phenology=Flowering late summer–fall.
|habitat=Usually wet, open sites
|elevation=10–600+ m
|distribution=N.B.;Nfld. and Labr. (Nfld.);N.S.;Ont.;Que.;Conn.;Del.;D.C.;Ga.;Ill.;Ind.;Iowa;Kans.;Ky.;Maine;Md.;Mass.;Mich.;Minn.;Miss.;N.J.;N.Y.;N.C.;Ohio;Pa.;S.C.;Tenn.;Vt.;Va.;W.Va.;Wis.
|reference=None
|publication title=Sp. Pl.
|publication year=1753
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse_grained_fna_xml/V19-20-21/V21_398.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Helianthinae
|genus=Helianthus
|species=Helianthus giganteus
}}<!--

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