View source for Arida ← Arida 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=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-undefined" data-properties=""><b>Annuals,</b> perennials, or subshrubs, 10–60(–90) cm; usually taprooted, sometimes rhizomatous. <b>Stems</b> erect to ascending or sprawling, often much branched, glabrous or hairy, sometimes stipitate-glandular or gland-dotted. <b>Leaves</b> basal (sometimes withering by flowering) and cauline; alternate; petiolate (basal) or sessile (cauline; sometimes succulent); 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. <b>Heads</b> radiate or discoid (<i>A. carnosa</i>), borne singly (terminal), or in cymiform or corymbiform arrays. <b>Involucres</b> turbinate to depressed-hemispheric, (3–12 ×) 4–16 mm. <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. <b>Receptacles</b> convex, indistinctly pitted (pit borders ± chartaceous, laciniate 0.1–0.5 mm, in <i>A. blepharophylla</i>), epaleate. <b>Ray</b> florets 0 (<i>A. carnosa</i>) or 8–80+, pistillate, fertile; corollas light to dark blue. <b>Disc</b> florets 12–100+, bisexual, fertile; corollas yellow, tubes 1/4–1/2 times ± funnelform throats (usually glabrous), lobes 5, erect, triangular (glabrous to minutely hairy). <b>Cypselae</b> ± dimorphic, narrowly oblong (thin-walled), 8–13-nerved per face (nerves filiform), sparsely to densely sericeous; ray cypselae (if present) obscurely 3-sided, rounded abaxially, disc ones slightly compressed laterally; pappi persistent, of 20–40, white or whitish (tawny in <i>A. blepharophylla</i>), barbellulate, apically attenuate bristles in 2–3 series (at most ± flattened and wider near sometimes slightly overlapping bases); ray lengths 1/3 to ± equaling disc. <b>x</b> = 5.</span><!-- -->{{Treatment/Body |distribution=Desert regions;sw United States;n Mexico. |discussion=<p>Species 9 (6 in the flora).</p><!-- --><p><i>Arida</i> belongs to a group of taxa once included within a broadly circumscribed <i>Machaeranthera</i> 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). <i>Arida</i> was recognized as a section of <i>Machaeranthera</i> 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 <i>Psilactis</i> 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 <i>Oönopsis</i>, <i>Pyrrocoma</i>, and <i>Xanthisma</i>, were closely related to various parts of <i>Machaeranthera</i>. 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). <i>Machaeranthera</i> was reduced to two species, and the remaining taxa were distributed in <i>Xanthisma</i>, <i>Dieteria</i>, and <i>Arida</i>.</p><!-- --><p>Data from chloroplast DNA restriction sites and nuclear ETS sequences support a close relationship between <i>Arida parviflora</i>, A. turneri, both with pinnate or 2-pinnate leaves, <i>A. riparia</i>, and <i>A. blepharophylla</i> (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. <i>Arida blepharophylla</i> 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 <i>Xanthisma</i> 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://bitbucket.org/aafc-mbb/fna-data-curation/src/2e0870ddd59836b60bcf96646a41e87ea5a5943a/coarse_grained_fna_xml/V19-20-21/V20_920.xml |tribe=Asteraceae tribe Astereae |genus=Arida }}<!-- -->[[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/ID/Basionym (view source) Template:Treatment/Publication (view source) Return to Arida.