View source for Vernonia

{{Treatment/ID
|accepted_name=Vernonia
|accepted_authority=Schreber
|publications={{Treatment/Publication
|title=Gen. Pl.
|place=2: 541. 1791
|year=1791
}}
|common_names=Ironweed
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Vernonieae;Vernonia
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Vernonieae]]</div><div class="higher-taxon"><small>genus</small>[[Vernonia]]</div></div>
|etymology=For William Vernon, d. 1711, English botanist
|volume=Volume 19
|mention_page=page 58, 67, 200, 201, 207
|treatment_page=page 206
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> 2–20(–30+) dm (rhizomatous or not). <b>Leaves</b> usually mostly cauline (rarely mostly basal or basal and cauline); sessile or petiolate; blades ovate, elliptic, lanceolate, oblanceolate, spatulate, linear, or filiform, bases usually ± cuneate (rounded-truncate in <i>V. pulchella</i>), margins usually toothed (rarely entire), apices acute to attenuate, abaxial faces usually ± scabrellous to strigillose or tomentose to pannose, sometimes glabrate or glabrous, usually resin-gland-dotted (sometimes ± pitted), adaxial faces ± scabrellous or glabrate, sometimes resin-gland-dotted (rarely pitted). <b>Heads</b> discoid, ± pedunculate, not subtended by foliaceous bracts, (6–)40–100+ in ± corymbiform to paniculiform arrays (6–)10–25+ cm diam. <b>Involucres</b> ± campanulate to obconic or hemispheric, 3–8(–11+) mm diam. <b>Phyllaries</b> 18–70+ in 4–7+ series, the outer ovate to lanceolate or subulate, inner ± lanceolate to oblong, all ± chartaceous, margins entire, often ciliolate, tips rounded (then sometimes apiculate), or acuminate, subulate, or filiform, faces glabrous or sparsely strigillose to tomentose, sometimes ± gland-dotted. <b>Florets</b> 9–30(–65+); corollas usually purplish or pink (rarely white), tubes longer than funnelform throats, lobes 5, lance-linear, ± equal. <b>Cypselae</b> ± columnar, sometimes arcuate, 8–10-ribbed, glabrous or ± strigillose to hirtellous, often resin-gland-dotted; pappi persistent, of 20–30+ outer, erose to subulate scales or bristles plus 20–40+ inner, longer, subulate to setiform scales or bristles. <b>x</b> = 17.</span><!--

-->{{Treatment/Body
|distribution=Mainly c;e North America;n Mexico;2–3 species in South America.
|discussion=<p>Species 20 or so (17 in the flora).</p><!--
--><p>The circumscription of <i>Vernonia</i> adopted here follows that of H. Robinson (1999).</p><!--
--><p>Vernonias hybridize; almost every one of the species recognized here has been noted as sometimes hybridizing with one or more others. Putative hybrid plants are usually intermediate between parentals in some traits; such plants may not “key” satisfactorily to any of the species treated here. Some putative hybrids have been named. <i>Vernonia</i> guadalupensis is “without much doubt a hybrid of <i>V. baldwinii</i> Torrey and <i>V. lindheimeri</i> Engelmann & Gray” (L. H. Shinners 1950); V. vulturina Shinners (known only from the type collection) may be a product of <i>V. baldwinii</i> × <i>V. marginata</i>; V. ×georgiana Bartlett may refer to <i>V. acaulis</i> × <i>V. angustifolia</i>. Additional putative hybrids (S. B. Jones 1964) are V. ×concinna Gleason (V. ovalifolia × <i>V. angustifolia</i>), V. ×dissimilis Gleason (V. altissima × <i>V. angustifolia</i>), and V. ×recurva Gleason (<i>V. pulchella</i> × <i>V. angustifolia</i>).</p><!--
--><p>In the key and descriptions, “l/w = ” refers to lengths divided by widths for blades of leaves; lengths of phyllaries include subulate to filiform tips (if any).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Phyllary tips usually subulate to filiform, sometimes acuminate
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Phyllary tips usually acute to rounded or rounded-apiculate, seldom acuminate
|[[#key-0-7| > 7]]
|-id=key-0-2
|2
|Leaves mostly basal (cauline leaves much smaller with narrower blades)
|[[Vernonia acaulis|Vernonia acaulis]]
|-id=key-0-2
|2
|Leaves mostly cauline (basal leaves wanting at flowering or ± like cauline)
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Involucres 11–15 mm diam.; phyllaries (50–)60–70+; florets 50–100+
|[[Vernonia arkansana|Vernonia arkansana]]
|-id=key-0-3
|3
|Involucres 4–8(–10) mm diam.; phyllaries 22–46(–60+); florets 12–45(–65)
|[[#key-0-4| > 4]]
|-id=key-0-4
|4
|Involucres ± campanulate to obconic; florets 12–24(–30+)
|[[#key-0-5| > 5]]
|-id=key-0-4
|4
|Involucres ± hemispheric; florets 30–45(–65)
|[[#key-0-6| > 6]]
|-id=key-0-5
|5
|Leaf blades (mid stem) lance-linear to filiform, 5–12 cm × 2–4(–8+) mm.
|[[Vernonia angustifolia|Vernonia angustifolia]]
|-id=key-0-5
|5
|Leaf blades (mid stem) oblanceolate to lance-linear, 3–7 cm × (5–)10–20+ mm
|[[Vernonia pulchella|Vernonia pulchella]]
|-id=key-0-6
|6
|Leaf blade l/w = 2.5–3.5(–4); pappi stramineous to whitish, outer bristles or subulate scales intergrading with inner ones
|[[Vernonia glauca|Vernonia glauca]]
|-id=key-0-6
|6
|Leaf blade l/w = (3.3–)4–6+; pappi fuscous to purplish, outer scales contrasting with inner bristles
|[[Vernonia noveboracensis|Vernonia noveboracensis]]
|-id=key-0-7
|7
|Phyllaries densely sericeo-tomentose to pannose
|[[#key-0-8| > 8]]
|-id=key-0-7
|7
|Phyllaries usually glabrous or puberulent to scabrellous (rarely sparsely arachno-tomentose)
|[[#key-0-9| > 9]]
|-id=key-0-8
|8
|Leaf blades adaxially densely sericeo-tomentose; florets 40–50+
|[[Vernonia larseniae|Vernonia larseniae]]
|-id=key-0-8
|8
|Leaf blades adaxially usually glabrate, sometimes sparsely arachno-tomentose; florets 12–24+
|[[Vernonia lindheimeri|Vernonia lindheimeri]]
|-id=key-0-9
|9
|Leaf blades abaxially glabrate (and pitted; best seen at 10× or greater, pits containing awl-shaped hairs or glands 0.1–0.5+ mm)
|[[#key-0-10| > 10]]
|-id=key-0-9
|9
|Leaf blades abaxially scabrellous, scaberulous, or puberulous to tomentose or pannose (not pitted)
|[[#key-0-13| > 13]]
|-id=key-0-10
|10
|Involucres obconic to hemispheric; cypselae 2–3 mm
|[[Vernonia texana|Vernonia texana]]
|-id=key-0-10
|10
|Involucres campanulate; cypselae 3–5 mm
|[[#key-0-11| > 11]]
|-id=key-0-11
|11
|Leaf blades 1–3+ mm wide; florets 10–12+
|[[Vernonia lettermannii|Vernonia lettermannii]]
|-id=key-0-11
|11
|Leaf blades (2.5–)5–20(–40) mm wide; florets (10–)15–25+
|[[#key-0-12| > 12]]
|-id=key-0-12
|12
|Peduncles (3–)10–35 mm; involucres (7–)9–11 mm; phyllary tips ± acuminate; inner pappi 8–9+ mm
|[[Vernonia marginata|Vernonia marginata]]
|-id=key-0-12
|12
|Peduncles 1–8(–12+) mm; involucres 5–7(–8+) mm; phyllary tips acute or rounded-apiculate; inner pappi 5–7+ mm
|[[Vernonia fasciculata|Vernonia fasciculata]]
|-id=key-0-13
|13
|Leaf blades 2–8+ mm wide
|[[Vernonia blodgettii|Vernonia blodgettii]]
|-id=key-0-13
|13
|Leaf blades 15–40(–75+) mm wide
|[[#key-0-14| > 14]]
|-id=key-0-14
|14
|Stems glabrous
|[[Vernonia flaccidifolia|Vernonia flaccidifolia]]
|-id=key-0-14
|14
|Stems puberulent to tomentose (sometimes glabrescent)
|[[#key-0-15| > 15]]
|-id=key-0-15
|15
|Leaf blades abaxially usually scabrellous (with appressed, awl-shaped hairs), sometimes glabrescent, not or sparsely resin-gland-dotted
|[[Vernonia gigantea|Vernonia gigantea]]
|-id=key-0-15
|15
|Leaf blades abaxially usually puberulous to tomentose or pannose (with ± erect, ± curled hairs), seldom glabrescent, conspicuously resin-gland-dotted
|[[#key-0-16| > 16]]
|-id=key-0-16
|16
|Involucres broadly campanulate to urceolate, (6–)7–10+ × 5–9+ mm; (phyllaries seldom resin-gland-dotted); florets 30–55
|[[Vernonia missurica|Vernonia missurica]]
|-id=key-0-16
|16
|Involucres broadly campanulate to hemispheric, 4–6(–8+) × 4–7+ mm; (phyllaries often resin-gland-dotted); florets (15–)20–25(–35+)
|[[Vernonia baldwinii|Vernonia baldwinii]]
|}
</div></div><!--

-->{{#Taxon:
name=Vernonia
|author=John L. Strother
|authority=Schreber
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Asteraceae
|distribution=Mainly c;e North America;n Mexico;2–3 species in South America.
|reference=None
|publication title=Gen. Pl.
|publication year=1791
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/eaa6e58056e40c9ef614d8f47aea294977a1a5e9/coarse_grained_fna_xml/V19-20-21/V19_250.xml
|tribe=Asteraceae tribe Vernonieae
|genus=Vernonia
}}<!--

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