View source for Laënnecia

{{Treatment/ID
|accepted_name=Laënnecia
|accepted_authority=Cassini in F. Cuvier
|publications={{Treatment/Publication
|title=in F. Cuvier, Dict. Sci. Nat. ed.
|place=2, 25: 91. 1822
|year=1822
}}
|basionyms=
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Laënnecia
|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>[[Laënnecia]]</div></div>
|etymology=For René-Théophile-Hyacinthe Laënnec, 1781–1826, French physician, inventor of the stethoscope
|volume=Volume 20
|mention_page=page 8, 9, 12, 349
|treatment_page=page 36
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole-organism atypical some measurement;whole-organism some measurement;whole-organism duration;whole-organism atypical some measurement;whole-organism some measurement;whole-organism duration"><b>Annuals </b>or perennials, 10–120 (–350+) cm (usually taprooted, sometimes with ± woody caudices).</span> <span class="statement" id="st-d0_s1" data-properties="stem orientation;stem architecture;stem architecture"><b>Stems </b>usually erect, simple or branched from bases or throughout.</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">sessile or petiolate;</span> <span class="statement" id="st-d0_s5" data-properties="blade arrangement or shape;blade arrangement or course or shape;blade shape;blade shape;blade shape;blade shape;blade shape;blade shape;ultimate margin shape;ultimate margin shape;face pubescence;face pubescence;face pubescence;face pubescence;face pubescence;face pubescence;face architecture;face architecture">blades (usually 1-nerved) elliptic, linear, oblanceolate, oblong, obovate, ovate, spatulate, sometimes 1–2-pinnately lobed, ultimate margins toothed or entire, faces glabrate, hirtellous, tomentose, or villous, usually stipitate and/or sessile-glandular as well.</span> <span class="statement" id="st-d0_s6" data-properties="head architecture;head architecture;array architecture;array architecture;array architecture"><b>Heads </b>obscurely radiate or disciform, borne in ± corymbiform, paniculiform, or racemiform arrays.</span> <span class="statement" id="st-d0_s7" data-properties="involucre shape;involucre diameter;involucre diameter"><b>Involucres </b>± turbinate, 2–7 [–10] mm diam.</span> <span class="statement" id="st-d0_s8" data-properties="phyllarie quantity;phyllarie fixation or orientation;phyllarie architecture;phyllarie shape;phyllarie size;phyllarie growth form or texture;series quantity;margin texture;margin pubescence;margin pubescence;margin pubescence;margin pubescence;margin pubescence;margin pubescence;margin architecture;margin architecture"><b>Phyllaries </b>20–40+ in 2–4 series, appressed (usually reflexed in fruit), 1-nerved (nerves not orange or brown), lanceolate to linear, ± unequal to subequal, ± herbaceous medially, margins ± membranous, glabrate, hirtellous, tomentose, or villous, usually stipitate and/or sessile-glandular as well.</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 atypical quantity;peripheral floret quantity;peripheral floret architecture;peripheral floret reproduction"><b>Peripheral </b>(“ray”) florets 20–100 (–200), pistillate, fertile;</span> <span class="statement" id="st-d0_s11" data-properties="corolla coloration">corollas yellowish (usually distally truncate or 2–5-toothed, sometimes with laminae 0.5–1+ mm).</span> <span class="statement" id="st-d0_s12" data-properties="disc-floret atypical quantity;disc-floret quantity;disc-floret reproduction;disc-floret reproduction"><b>Disc-</b>florets 2–20 [–30+], bisexual, fertile;</span> <span class="statement" id="st-d0_s13" data-properties="corolla coloration;tube height or length or size;lobe quantity;lobe orientation;lobe orientation;lobe shape">corollas yellowish, narrowly funnelform, tubes shorter than throats, lobes 5, erect or spreading, deltate (lengths 2–2.5+ times widths);</span> <span class="statement" id="st-d0_s14" data-properties="style-branch appendage shape">style-branch appendages deltate.</span> <span class="statement" id="st-d0_s15" data-properties="cypsela shape;cypsela shape;margin size or width;margin architecture or shape;face pubescence;face pubescence;face pubescence;face pubescence;face pubescence;face architecture;face architecture"><b>Cypselae </b>oblong to elliptic or obovate, compressed, margins thickened, riblike, faces glabrous, ± strigillose (hairs 0.05–0.1 mm), or densely sericeous (hairs 0.3–0.5 mm), often also stipitate and/or sessile-glandular;</span> <span class="statement" id="st-d0_s16" data-properties="pappus duration;pappus fragility;pappus life cycle;bristle quantity;bristle coloration;bristle variability;bristle architecture;bristle shape;series quantity;series quantity;series quantity">pappi persistent, ± fragile, or readily falling, of 9–30+, white to tawny, ± equal, barbellulate, apically attenuate bristles in 1 series, or 30–40+ bristles in 2 series (outer usually shorter).</span> <span class="statement" id="st-d0_s17" data-properties="x chromosome quantity">x = 9.</span><!--

-->{{Treatment/Body
|distribution=Mostly subtropical;tropical;and warm-temperate New World
|discussion=<p>Species ca. 18 (6 in the flora).</p><!--
--><p>G. L. Nesom (1990) argued for segregating some species from Conyza as members of Laënnecia. Although there are exceptions to each of the trends noted by Nesom, the rationale he presented is compelling. R. D. Noyes and L. H. Rieseberg (1999) demonstrated molecular differences that are consistent with treating laënnecias and conyzas in separate genera; at the same time, they showed Conyza to be “nested” within Erigeron.</p>
|tables=
|references={{Treatment/Reference
|id=nesom1990d
|text=Nesom, G. L. 1990. Taxonomy of the genus Laënnecia (Asteraceae: Astereae). Phytologia 68: 205–228.
}}
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Leaf blades densely to loosely tomentose (at least abaxially, sometimes glandular beneath the tomentum); pappi of 30–40+ bristles in 2 series
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Leaf blades usually hirtellous to villous and usually glandular, sometimes glabrate (usually sparsely and finely tomentose and with coarse, erect, multicellular hairs and stipitate- or sessile-glandular in L. schiedeana); pappi of 9–30 bristles in 1 series
|[[#key-0-3| > 3]]
|-id=key-0-2
|2
|Pistillate corollas: laminae 0.5–1 mm; cypselae pale tan to brownish, 2–3 mm
|[[Laënnecia eriophylla|Laënnecia eriophylla]]
|-id=key-0-2
|2
|Pistillate corollas: laminae 0; cypselae purplish, 1.3–1.5 mm
|[[Laënnecia filaginoides|Laënnecia filaginoides]]
|-id=key-0-3
|3
|Leaf blades mostly 1–2-pinnately lobed (lobes ovate to ± linear); pappi 2–3 mm
|[[#key-0-4| > 4]]
|-id=key-0-3
|3
|Leaf blades coarsely toothed or entire; pappi 3.5–4 mm
|[[#key-0-5| > 5]]
|-id=key-0-4
|4
|Bases of leaves obscurely, if at all, clasping; heads in racemiform or paniculiformarrays
|[[Laënnecia sophiifolia|Laënnecia sophiifolia]]
|-id=key-0-4
|4
|Bases of all or at least distal leaves clasping; heads in ± corymbiform arrays
|[[Laënnecia turnerorum|Laënnecia turnerorum]]
|-id=key-0-5
|5
|Leaf blades entire or distally toothed, faces usually sparsely and finely tomentose and with coarse, erect, multicellular hairs and stipitate- or sessile-glandular;pistillate corolla laminae 0.5–1+ mm
|[[Laënnecia schiedeana|Laënnecia schiedeana]]
|-id=key-0-5
|5
|Leaf blades coarsely toothed from near their bases or entire, faces usually both hirtellous tovillous and ± glandular-viscid, not tomentose; pistillate corollalaminae 0
|[[Laënnecia coulteri|Laënnecia coulteri]]
|}
</div></div><!--

-->{{#Taxon:
name=Laënnecia
|author=John L. Strother
|authority=Cassini in F. Cuvier
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=
|family=Asteraceae
|illustrator=Yevonn Wilson-Ramsey
|illustration copyright=Flora of North America Association
|distribution=Mostly subtropical;tropical;and warm-temperate New World
|reference=nesom1990d
|publication title=in F. Cuvier, Dict. Sci. Nat. ed.
|publication year=1822
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V19-20-21/V20_36.xml
|tribe=Asteraceae tribe Astereae
|genus=Laënnecia
|array architecture=racemiform;paniculiform;corymbiform
|blade arrangement or course or shape=linear
|blade arrangement or shape=elliptic
|blade shape=lobed;spatulate;ovate;obovate;oblong;oblanceolate
|bristle architecture=barbellulate
|bristle coloration=white;tawny
|bristle quantity=9;30
|bristle shape=attenuate
|bristle variability=equal
|corolla coloration=yellowish;yellowish
|cypsela shape=compressed;oblong;elliptic or obovate
|disc-floret atypical quantity=20;30
|disc-floret quantity=2;20
|disc-floret reproduction=fertile;bisexual
|face architecture=sessile-glandular;stipitate;sessile-glandular;stipitate
|face pubescence=sericeous;strigillose;sericeous;strigillose;glabrous;villous;tomentose;villous;tomentose;hirtellous;glabrate
|head architecture=disciform;radiate
|involucre diameter=2mm;7mm
|involucre shape=turbinate
|leaf architecture=petiolate;sessile
|leaf arrangement=alternate
|leaf position=cauline;basal
|lobe orientation=spreading;erect
|lobe quantity=5
|lobe shape=deltate
|margin architecture=sessile-glandular;stipitate
|margin architecture or shape=riblike
|margin pubescence=villous;tomentose;villous;tomentose;hirtellous;glabrate
|margin size or width=thickened
|margin texture=membranous
|pappus duration=persistent
|pappus fragility=fragile
|pappus life cycle=falling
|peripheral floret architecture=pistillate
|peripheral floret atypical quantity=100;200
|peripheral floret quantity=20;100
|peripheral floret reproduction=fertile
|phyllarie architecture=1-nerved
|phyllarie fixation or orientation=appressed
|phyllarie growth form or texture=herbaceous
|phyllarie quantity=20;40
|phyllarie shape=lanceolate;linear
|phyllarie size=less unequal;subequal
|receptacle architecture=epaleate
|receptacle architecture or pubescence or relief=smooth
|receptacle prominence or shape=flat
|receptacle relief=pitted
|series quantity=2;30;40
|stem architecture=branched;simple
|stem orientation=erect
|style-branch appendage shape=deltate
|tube height or length or size=shorter
|ultimate margin shape=entire;toothed
|whole-organism atypical some measurement=120cm;350cm
|whole-organism duration=perennial;annual
|whole-organism some measurement=10cm;120cm
|x chromosome quantity=9
}}<!--

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