View source for Machaeranthera

{{Treatment/ID
|accepted_name=Machaeranthera
|accepted_authority=Nees
|publications={{Treatment/Publication
|title=Gen. Sp. Aster.,
|place=13, 224. 1832
|year=1832
}}
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Machaeranthera
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Astereae]]</div><div class="higher-taxon"><small>genus</small>[[Machaeranthera]]</div></div>
|etymology=Latin machaera, sword, and anthera, anther, alluding to curved, sword-shaped anther appendages
|volume=Volume 20
|mention_page=page 12, 383, 385, 386, 395, 402, 403, 406
|treatment_page=page 394
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Annuals </b>or biennials, 5–100 cm; taprooted. <b>Stems</b> erect, much branched (when well developed), moderately to densely hairy, usually stipitate-glandular. <b>Leaves</b> basal (usually withering) and cauline; sessile; blades lanceolate to elliptic, pinnatifid, 2-pinnatifid, deeply lobed, or dissected (lobes aristate), ultimate margins entire, faces moderately to densely hairy, stipitate-glandular. <b>Heads</b> radiate, borne singly (on leafy peduncles 5–30 mm). <b>Involucres</b> broadly turbinate to hemispheric, (5–11 ×) 10–18 mm. <b>Phyllaries</b> 24–80(–100) in 3–6 series, appressed, spreading, or reflexed, 1-nerved (flat to keeled), lanceolate to linear, unequal, bases ± indurate, apices herbaceous, margins not scarious, faces proximally glabrous, distally moderately to densely hairy, stipitate-glandular. <b>Receptacles</b> flat to convex, pitted, epaleate. <b>Ray</b> florets 8–40(–50), pistillate, fertile; corollas blue, violet, or purple. <b>Disc</b> florets 14–160, bisexual, fertile; corollas yellow, tubes shorter than funnelform throats, lobes 5, erect, deltate to lanceolate; style-branch appendages lanceolate. <b>Cypselae</b> narrowly to broadly obovoid, slightly compressed, 8–18-ribbed, faces sparsely to densely hairy (hairs antrorse or appressed); pappi persistent, of 30–80 white to tawny, barbellate, apically attenuate bristles in 1–3 series. <b>x</b> = 4.</span><!--

-->{{Treatment/Body
|distribution=w North America;n Mexico.
|discussion=<p>Species 2 (2 in the flora).</p><!--
--><p>The relationships of Machaeranthera have long been unclear, and much disagreement has occurred about its circumscription. It has been included in Aster by some and maintained as a separate genus by others. In addition, all or parts of many other genera have been included in Machaeranthera by various authors, such as Xylorhiza, Dieteria, Arida, Xanthisma, Psilactis, and Rayjacksonia. Studies of chloroplast DNA and nuclear ribosomal DNA, in combination with chemical and cytological studies, do not support previous circumscriptions of Machaeranthera (D. R. Morgan and B. B. Simpson 1992; Morgan 1997, 2002). Those studies suggest that none of the other taxa are closest relatives of Machaeranthera, and they were treated as separate genera by Morgan and R. L. Hartman (2003).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Involucres hemispheric; phyllary apices spreading to reflexed; disc corolla lobes 0.3–0.7 mm, glabrous or glabrate
|[[Machaeranthera tanacetifolia|Machaeranthera tanacetifolia]]
|-id=key-0-1
|1
|Involucres broadly turbinate; phyllary apices appressed; disc corolla lobes 0.7–1 mm, hairy
|[[Machaeranthera tagetina|Machaeranthera tagetina]]
|}
</div></div><!--

-->{{#Taxon:
name=Machaeranthera
|author=David R. Morgan;Ronald L. Hartman
|authority=Nees
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Asteraceae
|illustrator=Bee F. Gunn
|distribution=w North America;n Mexico.
|reference=None
|publication title=Gen. Sp. Aster.,
|publication year=1832
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/9216fc802291cd3df363fd52122300479582ede7/coarse_grained_fna_xml/V19-20-21/V20_897.xml
|tribe=Asteraceae tribe Astereae
|genus=Machaeranthera
}}<!--

-->[[Category:Treatment]][[Category:Asteraceae tribe Astereae]]