View source for Arida

{{Treatment/ID
|accepted_name=Arida
|accepted_authority=(R. L. Hartman) D. R. Morgan & R. L. Hartman
|publications={{Treatment/Publication
|title=Sida
|place=20: 1410. 2003
|year=2003
}}
|common_names=Desert tansy-aster
|basionyms={{Treatment/ID/Basionym
|name=Machaeranthera sect. Arida
|authority=R. L. Hartman
|rank=section
|publication_title=Phytologia
|publication_place=68: 446. 1990
}}
|synonyms=
|hierarchy=Asteraceae;Asteraceae tribe Astereae;Arida
|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>[[Arida]]</div></div>
|etymology=Latin aridus, dry, alluding to xeric habitat typical of members
|volume=Volume 20
|mention_page=page 6, 12, 18, 394, 402, 403, 462
|treatment_page=page 401
}}<!--

--><span class="statement" id="st-d0_s0" data-properties="whole-organism duration"><b>Annuals,</b> perennials, or subshrubs, 10–60 (–90) cm;</span> <span class="statement" id="st-d0_s1" data-properties="whole-organism atypical some measurement;whole-organism some measurement;whole-organism architecture;whole-organism architecture;whole-organism duration;whole_organism atypical some measurement;whole_organism some measurement;whole_organism architecture;whole_organism growth form">usually taprooted, sometimes rhizomatous.</span> <span class="statement" id="st-d0_s2" data-properties="stem orientation;stem architecture;stem pubescence;stem pubescence;stem pubescence;stem coloration"><b>Stems </b>erect to ascending or sprawling, often much branched, glabrous or hairy, sometimes stipitate-glandular or gland-dotted.</span> <span class="statement" id="st-d0_s3" data-properties=""><b>Leaves </b>basal (sometimes withering by flowering) and cauline;</span> <span class="statement" id="st-d0_s4" data-properties="">alternate;</span> <span class="statement" id="st-d0_s5" data-properties="leaf position;leaf position;leaf arrangement;leaf architecture;leaf architecture">petiolate (basal) or sessile (cauline; sometimes succulent);</span> <span class="statement" id="st-d0_s6" data-properties="basal blade architecture;basal blade shape;basal blade shape;cauline blade shape;margin architecture or shape;margin shape;margin shape;margin shape;face pubescence;face pubescence;face pubescence">basal blades 1-nerved, linear to lanceolate, oblanceolate or obovate, cauline lanceolate to scalelike (bases tapered to clasping), margins entire, dentate, lacerate to deeply pinnatifid, or 2-pinnatifid (apices, including of lobes and teeth, apiculate to bristle-tipped, bristles 0.1–1 mm), faces glabrous or densely hairy, sometimes stipitate-glandular.</span> <span class="statement" id="st-d0_s7" data-properties="head architecture;head architecture;head arrangement;array architecture;array architecture"><b>Heads </b>radiate or discoid (A. carnosa), borne singly (terminal), or in cymiform or corymbiform arrays.</span> <span class="statement" id="st-d0_s8" data-properties="involucre shape;involucre length;involucre width"><b>Involucres </b>turbinate to depressed-hemispheric, (3–12 ×) 4–16 mm.</span> <span class="statement" id="st-d0_s9" data-properties="phyllarie quantity;phyllarie orientation;phyllarie orientation;phyllarie orientation;phyllarie orientation;phyllarie orientation;phyllarie architecture;phyllarie shape;phyllarie size;series quantity;base texture;apex growth form or texture;margin texture;face pubescence;face pubescence"><b>Phyllaries </b>40–150+ in 4–8 series, appressed, spreading, or reflexed, 1-nerved (flat to rounded or weakly keeled), linear-lanceolate to oblong-lanceolate, unequal, bases indurate to herbaceous, apices herbaceous, margins sometimes scarious, faces glabrous or moderately to densely hairy, sometimes stipitate-glandular.</span> <span class="statement" id="st-d0_s10" data-properties="receptacle shape;receptacle relief;receptacle architecture"><b>Receptacles </b>convex, indistinctly pitted (pit borders ± chartaceous, laciniate 0.1–0.5 mm, in A. blepharophylla), epaleate.</span> <span class="statement" id="st-d0_s11" data-properties="ray-floret presence;ray-floret quantity;ray-floret architecture;ray-floret reproduction"><b>Ray-</b>florets 0 (A. carnosa) or 8–80+, pistillate, fertile;</span> <span class="statement" id="st-d0_s12" data-properties="corolla coloration">corollas light to dark blue.</span> <span class="statement" id="st-d0_s13" data-properties="disc-floret quantity;disc-floret reproduction;disc-floret reproduction"><b>Disc-</b>florets 12–100+, bisexual, fertile;</span> <span class="statement" id="st-d0_s14" data-properties="corolla coloration;tube size or quantity;tube size or quantity;lobe quantity;lobe orientation;lobe shape">corollas yellow, tubes 1/4–1/2 times ± funnelform throats (usually glabrous), lobes 5, erect, triangular (glabrous to minutely hairy).</span> <span class="statement" id="st-d0_s15" data-properties="cypsela growth form;cypsela shape;cypsela architecture;cypsela pubescence"><b>Cypselae </b>± dimorphic, narrowly oblong (thin-walled), 8–13-nerved per face (nerves filiform), sparsely to densely sericeous;</span> <span class="statement" id="st-d0_s16" data-properties="ray cypsela shape;disc shape">ray cypselae (if present) obscurely 3-sided, rounded abaxially, disc ones slightly compressed laterally;</span> <span class="statement" id="st-d0_s17" data-properties="pappus duration;pappus coloration;pappus coloration;pappus architecture;bristle shape;series quantity">pappi persistent, of 20–40, white or whitish (tawny in A. blepharophylla), barbellulate, apically attenuate bristles in 2–3 series (at most ± flattened and wider near sometimes slightly overlapping bases);</span> <span class="statement" id="st-d0_s18" data-properties="disc lengths">ray lengths 1/3 to ± equaling disc.</span> <span class="statement" id="st-d0_s19" data-properties="ray quantity;x chromosome quantity">x = 5.</span><!--

-->{{Treatment/Body
|distribution=Desert regions;sw United States;n Mexico
|discussion=<p>Species 9 (6 in the flora).</p><!--
--><p>Arida belongs to a group of taxa once included within a broadly circumscribed Machaeranthera containing more than 36 species. This genus was generally distinguished by its taproots, spiny-toothed pinnatifid leaves, bristly-tipped phyllaries, blue ray corollas, epappose ray florets, and chromosome numbers of n = 4, 5, or 6 (A. Cronquist and D. D. Keck 1957; R. L. Hartman 1990; L. H. Shinners 1950b; B. L. Turner 1987b; Turner and D. B. Horne 1964). Arida was recognized as a section of Machaeranthera with epappose ray florets, unequal phyllaries, and a chromosome number of n = 5. Studies incorporating data from cpDNA restriction site analysis (D. R. Morgan and B. B. Simpson 1992) indicated that section Psilactis was not closely related to the other taxa and it was removed (Morgan 1993). Further studies utilizing DNA sequence data (Morgan 1997) suggested that other genera, such as Oönopsis, Pyrrocoma, and Xanthisma, were closely related to various parts of Machaeranthera. The combined phylogenetic information from molecular, morphologic, cytologic, and flavonoid analyses did not support recent taxonomies, so a new one was proposed by Morgan and Hartman (2003). Machaeranthera was reduced to two species, and the remaining taxa were distributed in Xanthisma, Dieteria, and Arida.</p><!--
--><p>Data from chloroplast DNA restriction sites and nuclear ETS sequences support a close relationship between Arida parviflora, A. turneri, both with pinnate or 2-pinnate leaves, A. riparia, and A. blepharophylla (D. R. Morgan 2003; Morgan and B. B. Simpson 1992). Conflicts between the two data sets were attributed to reticulate evolution resulting from occasional intergeneric crosses. Arida blepharophylla is somewhat unusual within the genus in being a short-lived perennial with rhizomes, basal rosettes of leaves, and receptacular scales (Morgan and R. L. Hartman 2003). These characters are similar to those found in Xanthisma and with these morphologic features as well as chloroplast versus nuclear DNA data, it may have evolved through intergeneric hybridization (Morgan 2003).</p>
|tables=
|references=
}}<!--

--><div class="treatment-key">
==Key==
<div class="treatment-key-group">
  
{| class="wikitable fna-keytable"
|-id=key-0-1
|1
|Ray cypselae epappose (except in occasional plants)
|[[#key-0-2| > 2]]
|-id=key-0-1
|1
|Ray cypselae pappose or ray florets 0 (in A. carnosa)
|[[#key-0-4| > 4]]
|-id=key-0-2
|2
|Midstems densely hispiduloso-glandular; s Arizona, s California, s Nevada, n Sonora (Mexico)
|[[Arida arizonica|Arida arizonica]]
|-id=key-0-2
|2
|Midstems glabrous or sparsely gland-dotted
|[[#key-0-3| > 3]]
|-id=key-0-3
|3
|Cauline leaf blades entire or toothed; w Texas
|[[Arida mattturneri|Arida mattturneri]]
|-id=key-0-3
|3
|Cauline leaf blades deeply pinnatifid; e Arizona, s Colorado, New Mexico, Utah, Chihuahua and Coahuila (Mexico)
|[[Arida parviflora|Arida parviflora]]
|-id=key-0-4
|4
|Leaves (at least some) pinnatifid to 2-pinnatifid
|[[Arida parviflora|Arida parviflora]]
|-id=key-0-4
|4
|Leaves entire or toothed
|[[#key-0-5| > 5]]
|-id=key-0-5
|5
|Ray florets 0
|[[Arida carnosa|Arida carnosa]]
|-id=key-0-5
|5
|Ray florets present.
|[[#key-0-6| > 6]]
|-id=key-0-6
|6
|Perennials, rhizomatous, forming vegetative rosettes; leaf margins entire with 8–20 cilia per side (cilia 0.4–1.5 mm); involucres broadly turbinate, 5–8 mm wide (fresh); phyllaries oblong to oblanceolate or obovate, broadly acute to short-acuminate
|[[Arida blepharophylla|Arida blepharophylla]]
|-id=key-0-6
|6
|Annuals; leaf margins entire, eciliate or with 1–8 cilia per side; involucres hemispheric, 10–16 mm wide (fresh); phyllaries linear-lanceolate, acute to acuminate
|[[Arida riparia|Arida riparia]]
|}
</div></div><!--

-->{{#Taxon:
name=Arida
|author=Ronald L. Hartman;David J. Bogler
|authority=(R. L. Hartman) D. R. Morgan & R. L. Hartman
|rank=genus
|parent rank=tribe
|synonyms=
|basionyms=Machaeranthera sect. Arida
|family=Asteraceae
|illustrator=Bee F. Gunn
|illustration copyright=Flora of North America Association
|distribution=Desert regions;sw United States;n Mexico
|reference=None
|publication title=Sida
|publication year=2003
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-fine-grained-xml.git/src/84153f6d59a0a91d69695978a64cee7560374f8e/V19-20-21/V20_920.xml
|tribe=Asteraceae tribe Astereae
|genus=Arida
|apex growth form or texture=herbaceous
|array architecture=corymbiform;cymiform
|basal blade architecture=1-nerved
|basal blade shape=linear;lanceolate oblanceolate or obovate
|base texture=indurate to herbaceous
|bristle shape=attenuate
|cauline blade shape=lanceolate;scalelike
|corolla coloration=yellow;light;dark blue
|cypsela architecture=8-13-nerved
|cypsela growth form=dimorphic
|cypsela pubescence=sericeous
|cypsela shape=oblong
|disc lengths=equaling
|disc shape=compressed
|disc-floret quantity=12;100
|disc-floret reproduction=fertile;bisexual
|face pubescence=stipitate-glandular;glabrous or;moderately densely hairy
|head architecture=discoid;radiate
|head arrangement=singly
|involucre length=[3mm;12mm
|involucre shape=turbinate;depressed-hemispheric
|involucre width=]4mm;16mm
|leaf architecture=sessile;petiolate
|leaf arrangement=alternate
|leaf position=cauline;basal
|lobe orientation=erect
|lobe quantity=5
|lobe shape=triangular
|margin architecture or shape=entire
|margin shape=lacerate;deeply pinnatifid or 2-pinnatifid
|margin texture=scarious
|pappus architecture=barbellulate
|pappus coloration=whitish;white
|pappus duration=persistent
|phyllarie architecture=1-nerved
|phyllarie orientation=reflexed;spreading;reflexed;spreading;appressed
|phyllarie quantity=40;150
|phyllarie shape=linear-lanceolate;oblong-lanceolate
|phyllarie size=unequal
|ray cypsela shape=rounded
|ray quantity=1/3
|ray-floret architecture=pistillate
|ray-floret presence=absent
|ray-floret quantity=8;80
|ray-floret reproduction=fertile
|receptacle architecture=epaleate
|receptacle relief=pitted
|receptacle shape=convex
|series quantity=2;3
|stem architecture=branched
|stem coloration=gland-dotted
|stem orientation=erect;ascending or sprawling
|stem pubescence=stipitate-glandular;hairy;glabrous
|tube size or quantity=1/4-1/2 times funnelform throats;1/4-1/2 times funnelform throats
|whole-organism architecture=rhizomatous;taprooted
|whole-organism atypical some measurement=60cm;90cm
|whole-organism duration=perennial;annual
|whole-organism some measurement=10cm;60cm
|whole_organism architecture=taprooted
|whole_organism atypical some measurement=60cm;90cm
|whole_organism growth form=subshrub
|whole_organism some measurement=10cm;60cm
|x chromosome quantity=5
}}<!--

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