View source for Ageratina ← Ageratina 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=Ageratina |accepted_authority=Spach |publications={{Treatment/Publication |title=Hist. Nat. Vég. |place=10: 286. 1841 |year=1841 }} |common_names=Snakeroot |basionyms= |synonyms= |hierarchy=Asteraceae;Asteraceae tribe Eupatorieae;Ageratina |hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Asteraceae]]</div><div class="higher-taxon"><small>tribe</small>[[Asteraceae tribe Eupatorieae]]</div><div class="higher-taxon"><small>genus</small>[[Ageratina]]</div></div> |etymology=Generic name Ageratum and Latin - ina, diminutive |volume=Volume 21 |mention_page=page 461, 462, 541, 552 |treatment_page=page 547 }}<!-- --><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> subshrubs, or shrubs [trees], mostly 20–220 cm. <b>Stems</b> usually erect, rarely scandent, sparsely to densely branched. <b>Leaves</b> cauline; mostly opposite (distal sometimes alternate); petiolate; blades 3(–5)-nerved from bases, usually deltate, lanceolate, ovate, rhombic, or triangular, sometimes orbiculate, margins entire, crenate, dentate, or serrate, faces glabrous or hispidulous, pilose, or puberulent, sometimes gland-dotted (<i>A. occidentalis</i>, <i>A. adenophora</i>). <b>Heads</b> discoid, usually in compact, (terminal and axillary) corymbiform arrays, sometimes borne singly. <b>Involucres</b> campanulate, 3–6 mm diam. <b>Phyllaries</b> persistent, 8–30 in 2(–3) series, 0- or 2-nerved, lanceolate to linear, ± equal (herbaceous). <b>Florets</b> 10–60; corollas white or lavender, throats obconic to campanulate (lengths 1.5–2 times diams.); styles: bases sometimes enlarged, glabrous, branches linear, seldom distally dilated. <b>Receptacles</b> convex (glabrous or hairy), epaleate. <b>Cypselae</b> prismatic or ± fusiform, usually 5-ribbed, scabrellous and/or gland-dotted; pappi usually persistent, sometimes fragile, rarely falling, of 5–40, barbellulate bristles in 1 series. <b>x</b> = 17.</span><!-- -->{{Treatment/Body |distribution=North America;Mexico;Central America;Andean South America. |discussion=<p>Species ca. 250 (14 in the flora).</p> |tables= |references={{Treatment/Reference |id=clewell1971a |text=Clewell, A. F. and J. W. Wooten. 1971. A revision of Ageratina (Compositae: Eupatorieae) from eastern North America. Brittonia 23: 123–143 }} }}<!-- --><div class="treatment-key"> ==Key== <div class="treatment-key-group"> {| class="wikitable fna-keytable" |-id=key-0-1 |1 |Shrubs |[[#key-0-2| > 2]] |-id=key-0-1 |1 |Perennials or subshrubs |[[#key-0-3| > 3]] |-id=key-0-2 |2 |Petioles (2–)3–5 mm; leaf blades 1–2 cm, margins entire or shallowly crenate, facesgland-dotted |[[Ageratina wrightii|Ageratina wrightii]] |-id=key-0-2 |2 |Petioles 3–10(–15) mm; leaf blades (2–)3–5(–7) cm, margins coarsely crenate, facesnot gland-dotted |[[Ageratina havanensis|Ageratina havanensis]] |-id=key-0-3 |3 |Leaves alternate on at least distal 1/4–1/2 of stems |[[#key-0-4| > 4]] |-id=key-0-3 |3 |Leaves opposite |[[#key-0-6| > 6]] |-id=key-0-4 |4 |Heads usually borne singly (rarely 2s or 3s); involucres 11–12 mm |[[Ageratina shastensis|Ageratina shastensis]] |-id=key-0-4 |4 |Heads usually 5–10 (axillary clusters usually forming elongate or broad aggregates); involucres 2.5–3.5(–4) mm |[[#key-0-5| > 5]] |-id=key-0-5 |5 |Leaves alternate on distal 1/4–1/2 of stems; involucres 3–3.5(–4) mm; corollas pink, bluish, or white tinged with purple (not orange-veined); cypselae sessile-glandular |[[Ageratina occidentalis|Ageratina occidentalis]] |-id=key-0-5 |5 |Leaves alternate (from bases to apices of stems); involucres 2.5–3 mm; corollaswhite (prominently orange-veined); cypselae eglandular |[[Ageratina thyrsiflora|Ageratina thyrsiflora]] |-id=key-0-6 |6 |Peduncles densely stipitate-glandular |[[Ageratina adenophora|Ageratina adenophora]] |-id=key-0-6 |6 |Peduncles puberulent, glabrous, or glabrescent (not glandular) |[[#key-0-7| > 7]] |-id=key-0-7 |7 |Flowering in spring; leaves usually narrowly lanceolate, 0.5–1.5 cm wide,apically long-acuminate; involucres 2.5–3 mm; cypselae glabrous |[[Ageratina paupercula|Ageratina paupercula]] |-id=key-0-7 |7 |Flowering in fall; leaves ovate to lanceolate-ovate, triangular, or lanceolate, (0.5–)1.5–9 cm wide, apically acute to acuminate; involucres (in A. jucunda 2.5–)3.5–7 mm; cypselae usually hairy (glabrous in A. altissima) |[[#key-0-8| > 8]] |-id=key-0-8 |8 |Leaves mostly sessile; heads in open, loose arrays, peduncles 10–60 mm |[[Ageratina lemmonii|Ageratina lemmonii]] |-id=key-0-8 |8 |Leaves distinctly petiolate; heads in compact clusters, ultimate peduncles 1–15(–20) mm |[[#key-0-9| > 9]] |-id=key-0-9 |9 |Petioles 1–22 mm (distal leaves greatly reduced in size well proximal to heads); leaf blades 2–7(–9) × 1.5–4 cm (relatively thick) |[[#key-0-10| > 10]] |-id=key-0-9 |9 |Petioles (5–)10–70 or 2–20 (in A. rothrockii) mm; leaf blades 2–11(–13) × 1.5–9 cm (relatively thin) |[[#key-0-11| > 11]] |-id=key-0-10 |10 |Petioles 1–8(–12) mm; leaf margins crenate or less commonlycrenate-serrate to dentate or subentire |[[Ageratina aromatica|Ageratina aromatica]] |-id=key-0-10 |10 |Petioles 7–15(–22) mm; leaf margins coarsely serrate or incised orless commonly crenate to subentire |[[Ageratina jucunda|Ageratina jucunda]] |-id=key-0-11 |11 |Leaves (yellow-green or grayish yellow-green): blades triangular to lanceolate-ovate or ovate, 2–5(–7) × 1.5–3.5(–4.5) cm; phyllariesusually granular-puberulent |[[Ageratina herbacea|Ageratina herbacea]] |-id=key-0-11 |11 |Leaves (green, rarely yellowish): blades lanceolate to lanceolate-ovate, 4–11(–13) × 2.5–9 cm; phyllaries glabrous, villous, or villous-puberulent |[[#key-0-12| > 12]] |-id=key-0-12 |12 |Stems glabrous; leaf blades broadly deltate-ovate (thin, delicate), apices obtuse; corolla lobes glabrous or sparselypuberulent |[[Ageratina luciae-brauniae|Ageratina luciae-brauniae]] |-id=key-0-12 |12 |Stems puberulent; leaf blades deltate-ovate to ovate or broadly lanceolate, apices acute to acuminate; corolla lobes short-villous |[[#key-0-13| > 13]] |-id=key-0-13 |13 |Peduncles 1–5 mm; involucres 4–5 mm; cypselae glabrous;e United States and Canada |[[Ageratina altissima|Ageratina altissima]] |-id=key-0-13 |13 |Peduncles 5–12(–20) mm; involucres 5–7 mm; cypselae sparsely and finely strigose-hirsute; Arizona, New Mexico, sw Texas |[[Ageratina rothrockii|Ageratina rothrockii]] |} </div></div><!-- -->{{#Taxon: name=Ageratina |author=Guy L. Nesom |authority=Spach |rank=genus |parent rank=tribe |synonyms= |basionyms= |family=Asteraceae |distribution=North America;Mexico;Central America;Andean South America. |reference=clewell1971a |publication title=Hist. Nat. Vég. |publication year=1841 |special status= |source xml=https://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V21_1389.xml |tribe=Asteraceae tribe Eupatorieae |genus=Ageratina }}<!-- -->[[Category:Treatment]][[Category:Asteraceae tribe Eupatorieae]] 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 Ageratina.