View source for Baccharis

{{Treatment/ID
|accepted_name=Baccharis
|accepted_authority=Linnaeus
|publications={{Treatment/Publication
|title=Sp. Pl.
|place=2: 860. 1753
|year=1753
}}, {{Treatment/Publication
|title=Gen. Pl. ed.
|place=5, 370. 1754
|year=1754
}}
|common_names=Groundsel-tree
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Baccharis
|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>[[Baccharis]]</div></div>
|etymology=For Roman god Bacchus, allusion obscure, perhaps used originally for different plant
|volume=Volume 20
|mention_page=page 3, 5, 6, 24, 34
|treatment_page=page 23
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Perennials,</b> subshrubs, shrubs, or trees, 10–600 cm (dioecious [rarely monoecious], usually glabrous, often resinous; bases woody, rarely rhizomatous). <b>Stems</b> (1–20+) usually erect or ascending, rarely prostrate (usually striate-angled, rarely terete and smooth; usually green), glabrous, glabrate, hispidulous, or villous, often resinous. <b>Leaves</b> cauline (sometimes withering and sparse or absent at flowering); alternate; sessile or petiolate; blades 1- or 3-nerved, linear, lanceolate, ovate, oblong, obovate, or rhombic (usually reduced distally), margins entire or coarsely serrate, faces usually glabrous, rarely hispidulous or villous, often gland-dotted and resinous. <b>Heads</b> (sessile or pedicellate, unisexual) discoid, usually in paniculiform or corymbiform, sometimes racemiform arrays or borne singly. <b>Involucres</b> cylindric to campanulate or hemispheric, 3–9 mm diam. <b>Phyllaries</b> 20–40 in 2–5 series (mid usually green, sometimes red or purple), 1-nerved, ovate to lanceolate, unequal, margins usually scarious, often erose or ciliate, sometimes keeled (midribs evident or not, apices obtuse to acute or acuminate, sometimes keeled), usually glabrous, rarely hispid. <b>Receptacles</b> flat, tholiform, or conic, pitted or smooth (glabrous, tomentose, or glandular), usually epaleate. <b>Functionally</b> staminate florets 10–50; corollas white to pale yellow, tubes about equal to narrowly funnelform throats, lobes 5, spreading-reflexed, deltate to lance-ovate (pappi of 20–40 equal, often crisped and minutely barbellate or distally plumose bristles). <b>Pistillate</b> florets 20–150; corollas whitish, filiform-tubular, lobes 5, spreading-reflexed, ± deltate to lance-ovate; style branches (glabrate, flattened), appendages lacking. <b>Cypselae</b> light brown, obovoid to cylindric, ± compressed, 5–10-nerved, glabrous or hispid; pappi persistent or falling, of 25–50 whitish to tawny, rarely brownish (elongating and usually surpassing phyllaries in fruit), minutely barbellate, apically attenuate bristles in 1–3 series. <b>x</b> = 9.</span><!--

-->{{Treatment/Body
|distribution=Mostly New World tropics and warm-temperate regions;especially diverse in South America.
|discussion=<p>Species 350–450 (21 in the flora).</p><!--
--><p><i>Baccharis</i> comprises mostly dioecious shrubs with gland-dotted leaves and is sister to the polygamo-dioecious genera Archibaccharis and Heterothalamus. Sections have been delimited within <i>Baccharis</i> (e.g., D. A. Giuliano 2001; Giuliano and G. L. Nesom 2003; Nesom 1990h, 1998). Species of <i>Baccharis</i> often occur in wet sites such as stream banks, washes, ditches, and marshes. Useful taxonomic characters include habit, branching structure, leaf shape, size, margins, and vestiture, arrangement of heads, and number of nerves on cypselae. Collectors should try to collect both staminate and pistillate individuals to facilitate identification.</p><!--
--><p>Hybridization and introgression have been found between <i>Baccharis halimifolia</i> and <i>B. neglecta</i>, and between <i>B. halimifolia</i> and <i>B. angustifolia</i>. Intermediates between <i>B. thesioides</i> and <i>B. bigelovii</i> have been collected in southern Arizona.</p><!--
--><p><i>Baccharis</i> is of little economic importance, except for species that are invasive or toxic to livestock (P. E. Boldt 1989). <i>Baccharis</i> is not generally palatable to cattle; it could become the only forage available as a result of overgrazing. In the southwestern United States, <i>B. pteronioides</i> is a hazard to cattle; <i>B. halimifolia</i>, <i>B. angustifolia</i>, and <i>B. glomeruliflora</i> cause similar problems in the eastern United States (G. E. Burrows and R. J. Tyrl 2001). <i>Baccharis pilularis</i> invades overgrazed or eroded rangelands in California and Oregon. <i>Baccharis halimifolia</i> has been introduced in Australia, infesting large areas along the eastern coast, prompting the search for biological control agents (Boldt).</p><!--
--><p>Neomolina F. H. Hellwig is an illegitimate, later homonym that has been applied to species included here in <i>Baccharis</i>.</p><!--
--><p>In key leads, references to pappi are to pappi on cypselae (i.e., in pistillate heads).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Stems hairy, villous, or hispidulous (at least distally among heads)
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Stems glabrous or glabrate
|[[#key-0-4| > 4]]
|-id=key-0-2
|2
|Leaves oblong or oblanceolate, (3–)5–13 mm wide; margins sharply serrate
|[[Baccharis plummerae|Baccharis plummerae]]
|-id=key-0-2
|2
|Leaves linear-lanceolate to narrowly oblanceolate, 1–4 mm wide, margins serrate or entire
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Proximal leaves linear-lanceolate, 5–17 × 1–2 mm, not gland-dotted or resinous, absent at flowering; distal leaves reduced, bractlike; Arizona, California, Nevada, Texas
|[[Baccharis brachyphylla|Baccharis brachyphylla]]
|-id=key-0-3
|3
|Proximal leaves linear to narrowly oblanceolate, (15–)20–45(–65) × 1–4(–5) mm, gland-dotted (adaxial faces), present at flowering; distal leaves usually well developed; Los Angeles County, California
|[[Baccharis malibuensis|Baccharis malibuensis]]
|-id=key-0-4
|4
|Perennials or subshrubs, stems 10–80 cm (much branched from bases)
|[[#key-0-5| > 5]]
|-id=key-0-4
|4
|Shrubs (aerial stems not dying back each year), mostly 60+ cm
|[[#key-0-7| > 7]]
|-id=key-0-5
|5
|Pistillate involucres 7–9 mm; phyllaries keeled (midribs dilated); leaves 10–40 × 1–4 mm, margins finely undulate
|[[Baccharis texana|Baccharis texana]]
|-id=key-0-5
|5
|Pistillate involucres 4–5 or 9–14 mm; phyllaries not keeled; leaves 5–30 × 1–2(–7) mm, margins entire, finely serrate, or irregularly dentate, not undulate
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Pistillate involucres 4–4.5 mm; pappi ca. 4 mm (tawny); leaf margins often irregularly toothed; flowering Jul–Sep; New Mexico, Texas
|[[Baccharis havardii|Baccharis havardii]]
|-id=key-0-6
|6
|Pistillate involucres 9–14 mm; pappi 15–20 mm (often brownish); leaf margins entire or finely serrate; flowering Apr–Jun; Arizona, Colorado, Kansas, New Mexico, Oklahoma, Texas, Utah
|[[Baccharis wrightii|Baccharis wrightii]]
|-id=key-0-7
|7
|Heads in compact racemiform arrays or glomerules (on relatively short lateral branchlets)
|[[#key-0-8| > 8]]
|-id=key-0-7
|7
|Heads in ± terminal corymbiform or paniculiform arrays
|[[#key-0-9| > 9]]
|-id=key-0-8
|8
|Stems ± terete or weakly striate, glandular, papillose-roughened; leaves clustered in fascicles, blades linear to lanceolate or spatulate, 5–12 × 1–5 mm, entire; heads (on leafy branches) in racemiform arrays
|[[Baccharis pteronioides|Baccharis pteronioides]]
|-id=key-0-8
|8
|Stems sharply striate-angled, glabrous or minutely scurfy; leaves not in fascicles, blades obovate or elliptic to rhombic, 20–60 × 8–40 mm (teeth 1–3 per side distal to middle); heads (sessile or subsessile) often in clusters of 3
|[[Baccharis glomeruliflora|Baccharis glomeruliflora]]
|-id=key-0-9
|9
|Plants broomlike (densely stemmed, branches ± parallel); leaves sparse or absent at flowering; heads borne singly (at tips of branches) or (± sessile on lateral branches) in paniculiform arrays
|[[#key-0-10| > 10]]
|-id=key-0-9
|9
|Plants bushy or sparingly branched, not broomlike; leaves present at flowering; heads in corymbiform or paniculiform arrays
|[[#key-0-12| > 12]]
|-id=key-0-10
|10
|Leaves obovate to broadly oblanceolate, 5–15 mm wide; heads (± sessile on lateral branches) in crowded paniculiform arrays; staminate corollas 2–3.5 mm
|[[Baccharis sergiloides|Baccharis sergiloides]]
|-id=key-0-10
|10
|Leaves linear to narrowly oblanceolate, 1–3 mm wide; heads borne singly or in clusters; staminate corollas 4–5 mm
|[[#key-0-11| > 11]]
|-id=key-0-11
|11
|Stems striate, sharply angled; involucres cylindric; phyllaries ovate to lanceolate, apices acute to rounded, glabrous; gravelly or sandy disturbed areas, Arizona, California, New Mexico, Texas
|[[Baccharis sarothroides|Baccharis sarothroides]]
|-id=key-0-11
|11
|Stems smooth, rounded; involucres funnelform; phyllaries lanceolate, narrowly tapered, usually glandular-scurfy; dense coastal chaparral, s California
|[[Baccharis vanessae|Baccharis vanessae]]
|-id=key-0-12
|12
|Proximal leaves rhombic, coarsely serrate (teeth 2–3 pairs distal to middles); pappi 8–12 mm
|[[Baccharis halimifolia|Baccharis halimifolia]]
|-id=key-0-12
|12
|Proximal leaves not rhombic, usually not coarsely serrate (if serrate, leaves less than 10 mm wide); pappi 3–12 mm
|[[#key-0-13| > 13]]
|-id=key-0-13
|13
|Leaves obovate, oblanceolate, or spatulate
|[[#key-0-14| > 14]]
|-id=key-0-13
|13
|Leaves linear, lanceolate, elliptic, oblong to narrowly oblanceolate
|[[#key-0-16| > 16]]
|-id=key-0-14
|14
|Leaf margins entire; s Florida
|[[Baccharis dioica|Baccharis dioica]]
|-id=key-0-14
|14
|Leaf margins coarsely and irregularly dentate or serrate; Arizona, California, New Mexico, Texas
|[[#key-0-15| > 15]]
|-id=key-0-15
|15
|Leaves not thickened, margins coarsely serrate or 2-serrate; array leaves reduced to bracts; cypselae 5-nerved; pappi 3–4.5 mm; Arizona, New Mexico, Texas
|[[Baccharis bigelovii|Baccharis bigelovii]]
|-id=key-0-15
|15
|Leaves thickened, margins entire or coarsely dentate (teeth 3–9); array leaves not reduced, often toothed; cypselae 8–10-nerved, pappi 6–9 mm; California
|[[Baccharis pilularis|Baccharis pilularis]]
|-id=key-0-16
|16
|Leaves linear, narrowly elliptic, or narrowly oblanceolate (1–5 mm wide)
|[[#key-0-17| > 17]]
|-id=key-0-16
|16
|Leaves 3–20 mm wide, lanceolate, or oblong to narrowly oblanceolate
|[[#key-0-19| > 19]]
|-id=key-0-17
|17
|Leaves linear to narrowly oblanceolate, margins sharply serrate; cypselae 5-nerved
|[[Baccharis plummerae|Baccharis plummerae]]
|-id=key-0-17
|17
|Leaves linear to narrowly elliptic, margins entire, serrate, or sparsely dentate; cypselae 10-nerved
|[[#key-0-18| > 18]]
|-id=key-0-18
|18
|Leaf margins mostly entire; brackish, marshy areas of Atlantic and Gulf coastal plains
|[[Baccharis angustifolia|Baccharis angustifolia]]
|-id=key-0-18
|18
|Leaf margins usually finely serrate (teeth shallow), sometimes nearly entire; disturbed open habitats, c Texas
|[[Baccharis neglecta|Baccharis neglecta]]
|-id=key-0-19
|19
|Leaves oblong to narrowly oblanceolate, margins entire or coarsely and irregularly ser-rate (teeth 2–3 pairs distal to middles); cypselae 8–10-nerved, pappi 8–12 mm
|[[Baccharis salicina|Baccharis salicina]]
|-id=key-0-19
|19
|Leaves lanceolate, linear-oblanceolate, or oblong, margins finely serrate (faces resinous); cypselae 5-nerved, pappi 4–6 mm
|[[#key-0-20| > 20]]
|-id=key-0-20
|20
|Plants rhizomatous, colonial; heads in dense, compact, terminal corymbiform arrays; cypselae minutely hispidulous; California, Oregon
|[[Baccharis douglasii|Baccharis douglasii]]
|-id=key-0-20
|20
|Plants not rhizomatous, not colonial; heads in loose paniculiform or corymbiform arrays; cypselae glabrous; s and w United States
|[[#key-0-21| > 21]]
|-id=key-0-21
|21
|Leaves 30–150 mm, margins entire or finely serrate from bases to apices, teeth blunt-tipped; heads in loose corymbiform arrays; cypselae 0.8–1.5 mm; sw United States
|[[Baccharis salicifolia|Baccharis salicifolia]]
|-id=key-0-21
|21
|Leaves 20–40(–80) mm, margins evenly serrate (teeth spinulose); heads in rounded paniculiform arrays; cypselae 1.5–2.2 mm; Arizona, New Mexico
|[[Baccharis thesioides|Baccharis thesioides]]
|}
</div></div><!--

-->{{#Taxon:
name=Baccharis
|author=Scott D. Sundberg†;David J. Bogler
|authority=Linnaeus
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Asteraceae
|illustrator=Yevonn Wilson-Ramsey
|illustration copyright=Flora of North America Association
|distribution=Mostly New World tropics and warm-temperate regions;especially diverse in South America.
|reference=None
|publication title=Sp. Pl.;Gen. Pl. ed.
|publication year=1753;1754
|special status=
|source xml=https://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/eaa6e58056e40c9ef614d8f47aea294977a1a5e9/coarse_grained_fna_xml/V19-20-21/V20_8.xml
|tribe=Asteraceae tribe Astereae
|genus=Baccharis
}}<!--

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