View source for Euthamia

{{Treatment/ID
|accepted_name=Euthamia
|accepted_authority=(Nuttall) Cassini in F. Cuvier
|publications={{Treatment/Publication
|title=in F. Cuvier, Dict. Sci. Nat. ed.
|place=2, 37: 471. 1825
|year=1825
}}
|basionyms={{Treatment/ID/Synonym
|name=Solidago subg. Euthamia
|authority=Nuttall
}}
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Euthamia
|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>[[Euthamia]]</div></div>
|etymology=Greek eu- , good, well, and thama, crowded, evidently alluding to branching pattern
|volume=Volume 20
|mention_page=page 8, 14, 96, 98, 108
|treatment_page=page 97
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials </b>or subshrubs, 40–200 cm (rhizomes creeping, fibrous-rooted). <b>Stems</b> erect (nearly terete), simple or branched, glabrous or hairy. <b>Leaves</b> cauline; alternate; sessile; blades (± uniform along stems) linear to lanceolate (40–130 mm), margins entire, faces glabrous or hairy, sparsely to densely gland-dotted (dots obscure or evident, 0.1–0.25 mm diam., 0–86 per mm²). <b>Heads</b> radiate, borne singly or (glomerulate) in corymbiform or paniculiform arrays. <b>Involucres</b> obconic to hemispheric, (2.5–6.3 ×) 2.1–8.1 mm. <b>Phyllaries</b> 11–29 in 3–5 series, 1-nerved (flat), linear to ovate, bases often stramineous or pale, margins chartaceous or weakly cartilaginous, not scarious (apices with green zones, erose to ciliate), abaxial faces glabrous, little to very resinous. <b>Receptacles</b> flat, pitted (pit borders ± fimbrillate), epaleate. <b>Ray</b> florets 7–22(–35) (usually more numerous than disc florets), pistillate, fertile; corollas yellow. <b>Disc</b> florets 3–22, bisexual, fertile; corollas yellow, tubes shorter than tubular to slender-funnelform throats, lobes 5, erect to ascending, oblong-lanceolate; style-branch appendages lanceolate. <b>Cypselae</b> oblong to narrowly ellipsoid, ± terete, 2–4-nerved, strigose; pappi persistent, of 20–30, white, ± equal, antrorsely barbellate, apically attenuate bristles in 1 series. <b>x</b> = 9.</span><!--

-->{{Treatment/Body
|distribution=North America;Mexico;introduced in Europe;Asia.
|discussion=<p>Species 5 (5 in the flora).</p><!--
--><p><i>Euthamia</i> was formerly included in <i>Solidago</i>. Arrangements of heads, gland-dotted leaves, and DNA sequence data demonstrate that <i>Euthamia</i> should be treated as distinct from <i>Solidago</i> (L. C. Anderson and J. B. Creech 1975; R. D. Noyes and L. H. Rieseberg 1999).</p><!--
--><p>Ambiguous and contradictory information has led to much debate about who named <i>Euthamia</i> (D. J. Sieren 1981; K. N. Gandhi 1999; G. L. Nesom 1999; J. L. Strother 2000). I consider correct authorship for this genus to be as given in Index Nominum Genericorum (http://ravenel.si.edu/botany/ing).</p><!--
--><p><i>Euthamia</i> is capable of tremendous phenotypic variation. Transitional aspects of a given plant are much more likely to be related to environmental factors than to introgression. Heights of arrays are determined by measuring from the summit of the plant to the bases of proximalmost head-bearing branches.</p>
|tables=
|references={{Treatment/Reference
|id=sieren1981a
|text=Sieren, D. J. 1981. The taxonomy of the genus Euthamia. Rhodora 83: 551–579.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems glabrous and glaucous; arrays of heads not flat-topped, lengths of proximal branches 0.18–0.56 times array heights (creating multistoried aspects to arrays); apices of inner phyllaries acute to acuminate
|[[Euthamia occidentalis|Euthamia occidentalis]]
|-id=key-0-1
|1
|Stems glabrous or hairy, not glaucous; arrays of heads usually flat-topped or rounded, lengths of proximal branches 0.5–1 times array heights; apices of inner phyllaries obtuse to acute
|[[#key-0-2| > 2]]
|-id=key-0-2
|2
|Disc corollas 2.5–3.3(–3.4) mm; involucres 3–4.7(–5.3) mm
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Disc corollas 3.3–4.8 mm; involucres (4–)4.5–6.3 mm
|[[#key-0-4| > 4]]
|-id=key-0-3
|3
|Stems glabrous or glabrate; leaf blades usually 1–3 mm wide (to 6 mm wide in some Maine and Nova Scotia populations), faces glabrous or glabrate, abundantly and prominently gland-dotted
|[[Euthamia caroliniana|Euthamia caroliniana]]
|-id=key-0-3
|3
|Stems glabrous or densely spreading-hirtellous; leaf blades usually 3–12 mm wide, faces glabrous or densely spreading-hirtellous, usually sparsely and obscurely gland-dotted
|[[Euthamia graminifolia|Euthamia graminifolia]]
|-id=key-0-4
|4
|Leaf blades linear to lanceolate, lengths 12–49 times widths, gradually reduced distally, faces abundantly and prominently gland-dotted, not pustulate; arrays (25–)35–60% of plant heights
|[[Euthamia gymnospermoides|Euthamia gymnospermoides]]
|-id=key-0-4
|4
|Leaf blades lanceolate to narrowly lanceolate, lengths 8–18 times widths, abruptly reduced distally, faces little and obscurely gland-dotted, sometimes pustulate;arrays 6–35% of plant heights
|[[Euthamia leptocephala|Euthamia leptocephala]]
|}
</div></div><!--

-->{{#Taxon:
name=Euthamia
|author=Arthur Haines
|authority=(Nuttall) Cassini in F. Cuvier
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=Solidago subg. Euthamia
|family=Asteraceae
|illustrator=Yevonn Wilson-Ramsey
|distribution=North America;Mexico;introduced in Europe;Asia.
|reference=sieren1981a
|publication title=in F. Cuvier, Dict. Sci. Nat. ed.
|publication year=1825
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/8f726806613d60c220dc4493de13607dd3150896/coarse_grained_fna_xml/V19-20-21/V20_190.xml
|tribe=Asteraceae tribe Astereae
|genus=Euthamia
}}<!--

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