View source for Helenium

{{Treatment/ID
|accepted_name=Helenium
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 886. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 377. 1754
|year=1754
|other_info_on_pub=(as Helenia)
}}
|common_names=Sneezeweed
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Gaillardiinae;Helenium
|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 Gaillardiinae]]</div><div class="higher-taxon"><small>genus</small>[[Helenium]]</div></div>
|etymology=For Helen of Troy
|volume=Volume 21
|mention_page=page 415, 416
|treatment_page=page 426
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Annuals </b>or perennials, 10–160 cm. <b>Stems</b> 1(–10), erect, simple or branched distally (usually ± winged by decurrent leaf bases), glabrous or sparsely to densely hairy. <b>Leaves</b> usually mostly cauline; mostly alternate (proximal sometimes opposite); petiolate or sessile; blades mostly elliptic, lanceolate, linear, oblanceolate, oblong, ovate, or spatulate, often pinnately lobed or pinnatifid, ultimate margins entire or toothed, faces glabrous or sparsely to densely hairy, gland-dotted. <b>Heads</b> radiate or discoid, borne singly or (2–300+) in paniculiform to corymbiform arrays. <b>Involucres</b> ± globose, hemispheric, obconic, or ovoid, 4–34 mm diam. <b>Phyllaries</b> persistent, 9–34(–40+) in (1–)2[–3] series (distinct or proximally connate, usually reflexed in fruit, glabrous or sparsely to densely hairy, gland-dotted). <b>Receptacles</b> conic, ± globose, hemispheric, or ovoid, pitted (glabrous), epaleate (rarely bearing setiform enations). <b>Ray</b> florets 0 or 7–34, pistillate and fertile or neuter; corollas yellow, yellow with purple streaks, reddish brown to red proximally and yellow distally, or reddish brown to red or purple throughout. <b>Disc</b> florets 75–1000+, bisexual, fertile; corollas yellow, purple, or yellow to yellow-green proximally and yellow-brown, brown or reddish brown to purple distally, tubes shorter than throats, lobes 4 or 5, ± deltate (style-branch apices penicillate or truncate). <b>Cypselae</b> mostly obpyramidal, 4–5-angled, glabrous or sparsely to densely hairy; pappi persistent, of 5–12 entire or ± lacerate, sometimes aristate scales. <b>x</b> = 17.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;West Indies (Cuba);Central America;South America.
|discussion=<p>Species ca. 32 (18 in the flora).</p><!--
--><p><i>Helenium</i> polyphyllum Small is apparently a hybrid between <i>H. autumnale</i> and <i>H. flexuosum</i>.</p>
|tables=
|references={{Treatment/Reference
|id=bierner1972a
|text=Bierner, M. W. 1972. Taxonomy of Helenium sect. Tetrodus and a conspectus of North American Helenium (Compositae). Brittonia 24: 331–355.
}}{{Treatment/Reference
|id=bierner1989a
|text=Bierner, M. W. 1989. Taxonomy of Helenium sect. Amarum (Asteraceae). Sida 13: 453–459.
}}{{Treatment/Reference
|id=rock1957a
|text=Rock, H. F. L. 1957. A revision of the vernal species of Helenium (Compositae). Rhodora 59: 101–116, 128–158, 168–178, 203–216.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems not winged
|[[Helenium amarum|Helenium amarum]]
|-id=key-0-1
|1
|Stems ± winged (by decurrent leaf bases)
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Ray florets usually 8–34, neuter (if rays 0, perennials from e or se United States)
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Ray florets usually 7–30, pistillate, fertile (if rays 0, plants either perennials from w United States or annuals)
|[[#key-0-8| > 8]]
|-id=key-0-3
|3
|Heads 1(–3); disc corollas mostly yellow, sometimes yellow-brown distally
|[[#key-0-4| > 4]]
|-id=key-0-3
|3
|Heads 1–80+; disc corollas usually purple, sometimes red-brown or yellow-brown distally or throughout
|[[#key-0-6| > 6]]
|-id=key-0-4
|4
|Pappus scales deeply lacerate; e Texas, sw Louisiana
|[[Helenium drummondii|Helenium drummondii]]
|-id=key-0-4
|4
|Pappus scales entire or slightly lacerate (never deeply lacerate); se Louisiana, s Mississippi, s Alabama, s Georgia, se South Carolina, s North Carolina, Florida
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Leaves of basal rosettes usually pinnatifid; peduncles hairy; cypselae hairy
|[[Helenium pinnatifidum|Helenium pinnatifidum]]
|-id=key-0-5
|5
|Leaves of basal rosettes usually entire; peduncles usually glabrous, sometimes sparsely hairy; cypselae glabrous
|[[Helenium vernale|Helenium vernale]]
|-id=key-0-6
|6
|Heads (1–)5–50(–80); pappi of aristate scales
|[[Helenium flexuosum|Helenium flexuosum]]
|-id=key-0-6
|6
|Heads 1–20; pappi of non-aristate scales
|[[#key-0-7| > 7]]
|-id=key-0-7
|7
|Stems densely hairy proximally; leaves moderately to densely hairy; pappi 0.3–0.5 mm; nc Arkansas
|[[Helenium campestre|Helenium campestre]]
|-id=key-0-7
|7
|Stems glabrous proximally; leaves glabrous or sparsely hairy; pappi 1–1.7 mm; se United States
|[[Helenium brevifolium|Helenium brevifolium]]
|-id=key-0-8
|8
|Perennials
|[[#key-0-9| > 9]]
|-id=key-0-8
|8
|Annuals
|[[#key-0-13| > 13]]
|-id=key-0-9
|9
|Stems unbranched or sparingly branched distally
|[[#key-0-10| > 10]]
|-id=key-0-9
|9
|Stems strongly branched distally
|[[#key-0-11| > 11]]
|-id=key-0-10
|10
|Peduncles usually densely hairy; pappi (2.5–)3–4.5 mm
|[[Helenium bolanderi|Helenium bolanderi]]
|-id=key-0-10
|10
|Peduncles sparsely to moderately hairy; pappi 1.3–2.2(–2.7) mm
|[[Helenium bigelovii|Helenium bigelovii]]
|-id=key-0-11
|11
|Rays usually 13–15, sometimes 0, corollas 3.8–10 mm; disc corollas yello to reddish brown or purple distally, lobes 4(–5)
|[[Helenium puberulum|Helenium puberulum]]
|-id=key-0-11
|11
|Rays 8–21, corollas 10–23 mm; disc corollas yellow to yellow-brown distally, lobes 5
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Leaves: basal blades oblanceolate, obovate, or spatulate (withered by flowering), mid blades usually dentate, distal blades entire or dentate; United States and s Canada
|[[Helenium autumnale|Helenium autumnale]]
|-id=key-0-12
|12
|Leaves: basal blades oblanceolate (usually present at flowering), mid blades usually entire, sometimes dentate; swampy meadows, Missouri, Virginia
|[[Helenium virginicum|Helenium virginicum]]
|-id=key-0-13
|13
|Pappi of aristate scales
|[[#key-0-14| > 14]]
|-id=key-0-13
|13
|Pappi of non-aristate scales
|[[#key-0-16| > 16]]
|-id=key-0-14
|14
|Disc corolla lobes 4(–5); California
|[[Helenium puberulum|Helenium puberulum]]
|-id=key-0-14
|14
|Disc corolla lobes 5; Arizona, Texas
|[[#key-0-15| > 15]]
|-id=key-0-15
|15
|Stems weakly winged (leaf bases scarcely decurrent from node to node); cypselae 2–2.9 mm; n Arizona
|[[Helenium arizonicum|Helenium arizonicum]]
|-id=key-0-15
|15
|Stems narrowly winged (leaf bases decurrent from node to node); cypselae 1–1.2 mm; s Texas
|[[Helenium linifolium|Helenium linifolium]]
|-id=key-0-16
|16
|Involucres globoid and distal leaves entire
|[[Helenium elegans|Helenium elegans]]
|-id=key-0-16
|16
|Involucres usually ovoid to obconic (if globoid, distal leaves serrate to undulate-serrate)
|[[#key-0-17| > 17]]
|-id=key-0-17
|17
|Distal leaves serrate to undulate-serrate; disc corolla lobes (4–)5
|[[Helenium microcephalum|Helenium microcephalum]]
|-id=key-0-17
|17
|Distal leaves entire; disc corolla lobes 4
|[[#key-0-18| > 18]]
|-id=key-0-18
|18
|Rays 10–15
|[[Helenium quadridentatum|Helenium quadridentatum]]
|-id=key-0-18
|18
|Rays 0
|[[Helenium thurberi|Helenium thurberi]]
|}
</div></div><!--

-->{{#Taxon:
name=Helenium
|author=Mark W. Bierner
|authority=Linnaeus
|rank=genus
|parent rank=subtribe
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=North America;Mexico;West Indies (Cuba);Central America;South America.
|reference=bierner1972a;bierner1989a;rock1957a
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;1754
|special status=
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V21_1066.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Gaillardiinae
|genus=Helenium
}}<!--

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[[Category:Treatment]]
[[Category:Asteraceae (tribe Heliantheae) subtribe Gaillardiinae]]
[[Category:Revised Since Print]]