View source for Helianthus debilis

{{Treatment/ID
|accepted_name=Helianthus debilis
|accepted_authority=Nuttall
|publications={{Treatment/Publication
|title=Trans. Amer. Philos. Soc., n. s.
|place=7: 367. 1841
|year=1841
}}
|special_status={{Treatment/ID/Special_status
|code=E
|label=Endemic
}}
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Helianthinae;Helianthus;Helianthus debilis
|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 debilis]]</div></div>
|volume=Volume 21
|mention_page=page 142, 143, 151, 153
|treatment_page=page 150
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Annuals </b>or perennials, 30–200 cm (taprooted). <b>Stems</b> decumbent to erect, glabrous, hirsute, or puberulent. <b>Leaves</b> mostly cauline; mostly alternate; petioles 1–7 cm; blades deltate-ovate, lance-ovate, or ovate, 2.5–14 × 1.8–13 cm, bases cordate to truncate or broadly cuneate, margins subentire to serrate, abaxial faces glabrate to hispid, not gland-dotted. <b>Heads</b> 1–3. <b>Peduncles</b> 9–50 cm. <b>Involucres</b> hemispheric, 10–22 mm diam. <b>Phyllaries</b> 20–30, lanceolate, 8–17 × 1–3 mm, apices acute to long-attenuate, abaxial faces glabrous or ± hispid, not gland-dotted. <b>Paleae</b> 7.5–8 mm, apices 3-toothed (middle teeth acuminate, usually glabrous or hispid, sometimes ± villous or bearded). <b>Ray</b> florets 11–20; laminae 12–23 mm. <b>Disc</b> florets 30+; corollas 4.5–5 mm, lobes usually reddish, sometimes yellow; anthers dark, appendages dark (style branches usually reddish, rarely yellow). <b>Cypselae</b> 2.5–3.2 mm, glabrous or sparsely hairy; pappi of 2 lanceolate or lance-linear scales 1.2–2.5 mm.</span><!--

-->{{Treatment/Body
|distribution=Ala.;Conn.;Fla.;Ga.;La.;Mass.;Md.;Mich.;Miss.;N.C.;N.H.;N.Y.;Pa.;R.I.;S.C.;Tex.;Va.;Vt.;W.Va.
|discussion=<p>Subspecies 5 (5 in the flora).</p><!--
--><p>C. B. Heiser (1956) placed 8 subspecies in <i>Helianthus debilis</i>; he noted that alternative taxonomic treatments might recognize these in as many as three species, or expand the single species to include <i>H. petiolaris</i>. Later, Heiser et al. (1969) separated three of the subspecies as <i>H. praecox</i>. Isozyme data (R. P. Wain 1982, 1983; L. H. Rieseberg and M. F. Doyle 1989) show that all are closely related. Documented hybridization with <i>H. annuus</i> further complicates the situation. The treatment by Heiser et al. is followed here.</p><!--
--><p><i>Helianthus debilis</i> is adventive beyond the Atlantic and Gulf coasts of the United States.</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems decumbent; peduncles 9–20(–22) cm
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Stems erect; peduncles (15–)20–50 cm
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Stems glabrous or puberulent; leaf blades serrulate or shallowly, regularly serrate, abaxial faces sparsely, if at all, gland-dotted
|[[Helianthus debilis subsp. debilis|Helianthus debilis subsp. debilis]]
|-id=key-0-2
|2
|Stems hirsute; leaf blades deeply, irregularly serrate, abaxial faces densely gland-dotted
|[[Helianthus debilis subsp. vestitus|Helianthus debilis subsp. vestitus]]
|-id=key-0-3
|3
|Leaves 8–14 cm; peduncles (relatively slender) 20–40 cm; discs 10–15(–17) mm diam
|[[Helianthus debilis subsp. silvestris|Helianthus debilis subsp. silvestris]]
|-id=key-0-3
|3
|Leaves 2.5–9 cm; peduncles (not notably slender) 10–50 cm; discs 14–20 mm diam
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Leaf blades usually deeply, irregularly serrate; peduncles 10–25(–30) cm; ray lami-nae 12–20(–22) mm
|[[Helianthus debilis subsp. tardiflorus|Helianthus debilis subsp. tardiflorus]]
|-id=key-0-4
|4
|Leaf blades usually shallowly, regularly serrate; peduncles 25–50 cm; ray laminae (15–)20–23 mm
|[[Helianthus debilis subsp. cucumerifolius|Helianthus debilis subsp. cucumerifolius]]
|}
</div></div><!--

-->{{#Taxon:
name=Helianthus debilis
|authority=Nuttall
|rank=species
|parent rank=genus
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=Ala.;Conn.;Fla.;Ga.;La.;Mass.;Md.;Mich.;Miss.;N.C.;N.H.;N.Y.;Pa.;R.I.;S.C.;Tex.;Va.;Vt.;W.Va.
|reference=None
|publication title=Trans. Amer. Philos. Soc., n. s.
|publication year=1841
|special status=Endemic
|source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V21_349.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Helianthinae
|genus=Helianthus
|species=Helianthus debilis
}}<!--

-->[[Category:Treatment]][[Category:Helianthus]]