View source for Conyza ← Conyza You do not have permission to edit this page, for the following reason: The action you have requested is limited to users in the group: Users. You can view and copy the source of this page. {{Treatment/ID |accepted_name=Conyza |accepted_authority=Lessing |publications={{Treatment/Publication |title=Syn. Gen. Compos., |place=203. 1832 |year=1832 }} |common_names=Horseweed |basionyms= |synonyms= |hierarchy=Asteraceae;Asteraceae tribe Astereae;Conyza |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>[[Conyza]]</div></div> |etymology=Ancient name for fleabane; perhaps from Greek konops, flea, or konis, dust, alluding to powdered dry plant being used to repel insects |volume=Volume 20 |mention_page=page 3, 9, 11, 36, 257, 349 |treatment_page=page 348 }}<!-- --><span class="statement" id="st-d0_s0" data-properties="whole-organism atypical some measurement;whole-organism some measurement;whole-organism duration"><b>Annuals </b>[perennials], 10–120 (–350+) cm.</span> <span class="statement" id="st-d0_s1" data-properties="stem orientation;stem architecture;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence;stem pubescence"><b>Stems </b>usually erect, branched mostly distally (spreading and branched throughout in C. ramosissima), glabrous or hispid, hispidulous, strigillose, or strigose.</span> <span class="statement" id="st-d0_s2" data-properties=""><b>Leaves </b>basal and cauline (mostly cauline at flowering);</span> <span class="statement" id="st-d0_s3" data-properties="">alternate;</span> <span class="statement" id="st-d0_s4" data-properties="leaf position;leaf position;leaf arrangement;leaf architecture;leaf architecture">petiolate or sessile;</span> <span class="statement" id="st-d0_s5" data-properties="blade shape;margin shape;margin position;margin shape;margin shape;face pubescence;face pubescence;face pubescence;face pubescence;face pubescence;face pubescence">blades mostly lanceolate to oblanceolate or linear, margins rarely lobed, ultimate toothed or entire, faces usually hispid, hispidulous, strigillose, or strigose (eglandular).</span> <span class="statement" id="st-d0_s6" data-properties="head architecture;head architecture;head architecture;head architecture"><b>Heads </b>radiate or disciform, usually in spreading to strict, paniculiform or corymbiform arrays (borne ± singly in C. ramosissima).</span> <span class="statement" id="st-d0_s7" data-properties="involucre shape;involucre diameter;involucre diameter"><b>Involucres </b>± turbinate, 2–5 [–7+] mm diam.</span> <span class="statement" id="st-d0_s8" data-properties="phyllarie quantity;phyllarie fixation or orientation;phyllarie size;phyllarie architecture;phyllarie shape;phyllarie size;phyllarie growth form or texture;series quantity;margin texture;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence;abaxial face pubescence"><b>Phyllaries </b>20–40+ in 2–4 series, appressed (usually reflexed in fruit), the larger usually 3-nerved (midnerves orange to brownish; not notably keeled), lanceolate to linear, unequal, ± herbaceous medially, margins membranous, abaxial faces glabrous or hirsutulous, hispidulous, or strigose.</span> <span class="statement" id="st-d0_s9" data-properties="receptacle prominence or shape;receptacle relief;receptacle architecture or pubescence or relief;receptacle architecture"><b>Receptacles </b>± flat, pitted or smooth, epaleate.</span> <span class="statement" id="st-d0_s10" data-properties="peripheral floret architecture;peripheral floret reproduction;peripheral floret quantity;series quantity;corolla coloration;corolla quantity;series quantity;corolla coloration"><b>Peripheral </b>(“ray”) florets pistillate, fertile: either 20–45+ in 1–2+ series, corollas white to purplish (filiform with laminae filiform to elliptic, 0.1–1 [–1.5+] mm), or 20–150+ in 2–5+ series, corollas ochroleucous (filiform, laminae lacking, distally truncate or 2–5-toothed).</span> <span class="statement" id="st-d0_s11" data-properties="disc-floret quantity;disc-floret reproduction;disc-floret reproduction"><b>Disc-</b>florets 3–30+, bisexual, fertile;</span> <span class="statement" id="st-d0_s12" data-properties="corolla coloration;tube height or length or size;lobe quantity;lobe orientation;lobe orientation;lobe shape">corollas yellowish (nerves sometimes prominently resinous), tubes shorter than narrowly funnelform throats, lobes 5, erect or spreading, deltate;</span> <span class="statement" id="st-d0_s13" data-properties="style-branch appendage shape">style-branch appendages deltate.</span> <span class="statement" id="st-d0_s14" data-properties="cypsela shape;cypsela shape;cypsela architecture;face pubescence;face pubescence;face architecture"><b>Cypselae </b>compressed, oblong to elliptic, 1-nerved on each edge, faces glabrous or strigillose (hairs 0.05–0.1+ mm), eglandular;</span> <span class="statement" id="st-d0_s15" data-properties="pappus duration;pappus coloration;pappus coloration;pappus coloration;pappus coloration;pappus coloration;pappus variability;pappus architecture;series quantity">pappi persistent, of 15–25+ pinkish, sordid, tawny, or white, ± equal, barbellulate, apically attenuate bristles in 1 series.</span> <span class="statement" id="st-d0_s16" data-properties="bristle shape;x chromosome quantity">x = 9.</span><!-- -->{{Treatment/Body |distribution=Widespread;mostly in subtropical and warm-temperate zones |discussion=<p>Species 25–40+ (4 in the flora).</p><!-- --><p>Distinctions between Conyza and Erigeron, as usually circumscribed in the past 50+ years, are not always clear. Usually, conyzas have unequal (graduated) phyllaries and 2–20+ times as many pistillate florets as bisexual florets in each head (rarely more bisexual than pistillate), and corollas of pistillate florets either lack laminae or have laminae usually less than 1(–1.5) mm. Erigerons usually have subequal phyllaries and more bisexual than pistillate florets (rarely more pistillate than bisexual) and corollas of pistillate florets (if any) usually have laminae 2–10+ mm.</p><!-- --><p>In studies by R. D. Noyes (2000) and by Noyes and L. H. Rieseberg (1999), Conyza, as traditionally circumscribed, was found to be nested within Erigeron and to be para- and/or polyphyletic. Here, absent an alternate taxonomy, four species traditionally treated in Conyza are retained in Conyza and a separate suite of six species that have usually been included in Conyza are treated in Laënnecia.</p> |tables= |references={{Treatment/Reference |id=cronquist1943a |text=Cronquist, A. 1943. The separation of Erigeron from Conyza. Bull. Torrey Bot. Club 70: 629–632. 1943. }}{{Treatment/Reference |id=nesom1990i |text=Nesom, G. L. 1990c. Further definition of Conyza (Asteraceae: Astereae). Phytologia 68: 229–233. }} }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Plants spreading, 5–25 cm, branched throughout (stems usually ± strigose); receptacles 0.7–1 mm diam. in fruit |[[Conyza ramosissima|Conyza ramosissima]] |-id=key-0-1 |1 |Plants erect, (10–)30–350+ cm, branched mostly distally; receptacles 1–5 mm diam. in fruit |[[#key-0-2| > 2]] |-id=key-0-2 |2 |Phyllaries usually hispidulous or strigose; receptacles 3–5 mm diam. in fruit; pistillate florets 60–150+; pappi 3–4+ mm |[[Conyza bonariensis|Conyza bonariensis]] |-id=key-0-2 |2 |Phyllaries glabrous or sparsely strigose; receptacles 1–3 mm diam. in fruit; pistillate florets 20–45+; pappi 2–3 mm |[[#key-0-3| > 3]] |-id=key-0-3 |3 |Phyllaries usually sparsely strigose; corollas of pistillate florets with laminae 0 or to 0.3 mm; cypselae pale tan (usually some in each head with reddish nerves) |[[Conyza floribunda|Conyza floribunda]] |-id=key-0-3 |3 |Phyllaries usually glabrous, sometimes sparsely strigose; corollas of pistillate florets with laminae 0.3–1+ mm; cypselae uniformly pale tan to light gray-brown |[[Conyza canadensis|Conyza canadensis]] |} </div></div><!-- -->{{#Taxon: name=Conyza |author=John L. Strother |authority=Lessing |rank=genus |parent rank=tribe |synonyms= |basionyms= |family=Asteraceae |illustrator=Yevonn Wilson-Ramsey |illustration copyright=Flora of North America Association |distribution=Widespread;mostly in subtropical and warm-temperate zones |reference=cronquist1943a;nesom1990i |publication title=Syn. Gen. Compos., |publication year=1832 |special status= |source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V19-20-21/V20_802.xml |tribe=Asteraceae tribe Astereae |genus=Conyza |abaxial face pubescence=strigose;hispidulous;hirsutulous;glabrous;strigose;hispidulous;hirsutulous;glabrous;strigose;hispidulous;hirsutulous;glabrous |blade shape=mostly lanceolate;oblanceolate or linear |bristle shape=attenuate |corolla coloration=yellowish;ochroleucous;white;purplish |corolla quantity=20;150 |cypsela architecture=1-nerved |cypsela shape=oblong;elliptic |disc-floret quantity=3;30 |disc-floret reproduction=fertile;bisexual |face architecture=eglandular |face pubescence=strigillose;glabrous;strigose;strigillose;strigose;strigillose;hispidulous;hispid |head architecture=corymbiform;paniculiform;disciform;radiate |involucre diameter=2mm;5mm |involucre shape=turbinate |leaf architecture=sessile;petiolate |leaf arrangement=alternate |leaf position=cauline;basal |lobe orientation=spreading;erect |lobe quantity=5 |lobe shape=deltate |margin position=ultimate |margin shape=entire;toothed;lobed |margin texture=membranous |pappus architecture=barbellulate |pappus coloration=white;tawny;white;tawny;sordid |pappus duration=persistent |pappus variability=equal |peripheral floret architecture=pistillate |peripheral floret quantity=20;45 |peripheral floret reproduction=fertile |phyllarie architecture=3-nerved |phyllarie fixation or orientation=appressed |phyllarie growth form or texture=herbaceous |phyllarie quantity=20;40 |phyllarie shape=lanceolate;linear |phyllarie size=unequal;larger |receptacle architecture=epaleate |receptacle architecture or pubescence or relief=smooth |receptacle prominence or shape=flat |receptacle relief=pitted |series quantity=1;2;5 |stem architecture=branched |stem orientation=erect |stem pubescence=strigose;strigillose;hispidulous;hispid;glabrous;strigose;strigillose;hispidulous;hispid;glabrous;strigose;strigillose;hispidulous;hispid;glabrous;strigose;strigillose;hispidulous;hispid;glabrous |style-branch appendage shape=deltate |tube height or length or size=shorter |whole-organism atypical some measurement=120cm;350cm |whole-organism duration=annual |whole-organism some measurement=10cm;120cm |x chromosome quantity=9 }}<!-- -->[[Category:Treatment]][[Category:Asteraceae tribe Astereae]] Templates used on this page: Template:Asteraceae (view source) Template:Treatment/AuthorLink (view source) Template:Treatment/Body (view source) Template:Treatment/Body/Maps (view source) Template:Treatment/ID (view source) Template:Treatment/Publication (view source) Template:Treatment/Reference (view source) Return to Conyza.