View source for Helianthus occidentalis

{{Treatment/ID
|accepted_name=Helianthus occidentalis
|accepted_authority=Riddell
|publications={{Treatment/Publication
|title=W. J. Med. Phys. Sci.
|place=9: 577. 1836
|year=1836
}}
|common_names=Western sunflower
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Heliantheae;Asteraceae (tribe Heliantheae) subtribe Helianthinae;Helianthus;Helianthus occidentalis
|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 occidentalis]]</div></div>
|volume=Volume 21
|mention_page=page 144, 146, 147, 156, 163
|treatment_page=page 160
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> 60–150 cm (rhizomatous, sometimes stoloniferous as well). <b>Stems</b> (often reddish) erect, pilose to appressed-hairy proximally. <b>Leaves</b> mostly basal; opposite; petioles 2.5–10 cm; blades oblong-lanceolate or elliptic to ovate, 5–20 × 1.5–7 cm, bases cuneate, margins entire or serrulate, abaxial faces scabrous to hispidulous, gland-dotted (cauline usually smaller, rarely 2–4 pairs well developed). <b>Heads</b> 1–4(–12). <b>Peduncles</b> 1–14 cm. <b>Involucres</b> cylindric, 9–14 mm diam. <b>Phyllaries</b> 20–25, lanceolate, 4.5–7(–11) × 1.5–2.5 mm, (margins usually ciliate) apices acute to short-acuminate, abaxial faces glabrate to sparsely pilose (hairs moniliform), not gland-dotted. <b>Paleae</b> 5–7 mm, subentire to 3-toothed (shortly mucronate). <b>Ray</b> florets 8–14; laminae 18–22 mm (abaxial faces densely gland-dotted). <b>Disc</b> florets 50+; corollas 4.5–5.5 mm, lobes yellow; anthers dark brown or black, appendages yellow. <b>Cypselae</b> 3–4(–5) mm, sparsely villous or glabrate; pappi of 2 aristate scales 1.5–2.8 mm plus 0–4 deltate scales 0.4–1 mm. <b>2n</b> = 34 (subspecies unknown).</span><!--

-->{{Treatment/Body
|distribution=c;e United States.
|discussion=<p>Subspecies 2 (2 in the flora).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Leaves entire or nearly so, scabrous or hirsute, rough to touch
|[[Helianthus occidentalis subsp. occidentalis|Helianthus occidentalis subsp. occidentalis]]
|-id=key-0-1
|1
|Leaves usually serrate, strigose or glabrous, smooth to touch
|[[Helianthus occidentalis subsp. plantagineus|Helianthus occidentalis subsp. plantagineus]]
|}
</div></div><!--

-->{{#Taxon:
name=Helianthus occidentalis
|authority=Riddell
|rank=species
|parent rank=genus
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=c;e United States.
|reference=None
|publication title=W. J. Med. Phys. Sci.
|publication year=1836
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse_grained_fna_xml/V19-20-21/V21_382.xml
|tribe=Asteraceae tribe Heliantheae
|subtribe=Asteraceae (tribe Heliantheae) subtribe Helianthinae
|genus=Helianthus
|species=Helianthus occidentalis
}}<!--

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