Arida arizonica

(R. C. Jackson & R. R. Johnson) D. R. Morgan & R. L. Hartman

Sida 20: 1413. 2003.

Common names: Desert tansy-aster
Illustrated
Basionyms: Machaeranthera arizonica R. C. Jackson & R. R. Johnson Rhodora 69: 476, fig. 1. 1967
Synonyms: Machaeranthera ammophila Reveal Machaeranthera arida B. L. Turner & D. B. Horne Machaeranthera coulteri var. arida (B. L. Turner & D. B. Horne) B. L. Turner
Treatment appears in FNA Volume 20. Treatment on page 403. Mentioned on page 402.

Annuals, 5–40 cm; taproots slender. Stems usually 1, sometimes 2–6+, erect to ascending, slender, usually much branched from base, divaricately so, densely hispiduloso-glandular, viscid. Leaves basal and cauline; proximal petiolate, distal sessile, often clasping; blades oblanceolate to oblong, reduced distally, 10–50 (–70) × 1–25 mm, herbaceous, margins coarsely dentate or pinnatifid, apices of teeth or lobes spiny-tipped, faces glandular-hispidulous. Heads borne singly (terminal),often in loose, leafy, corymbiform arrays. Involucres hemispheric, 4–5 × 6–8 mm (fresh). Phyllaries in 2–3 series, appressed to reflexed distally, lanceolate, 1–5 mm, bases whitish, margins ± entire, apices green or sometimes purplish, acute, faces hispiduloso-glandular. Ray-florets 20–35+; laminae lavender to whitish, 5–7 mm, coiling after flowering. Disc-florets 25–40+; corollas yellow, 3–6 mm. Cypselae oblanceolate, 1.4–2 mm, smooth, faces sparsely sericeous; pappi: ray 0; disc white, terete, 1.5–3 mm. 2n = 10.


Phenology: Flowering Mar–Nov.
Habitat: Dry, open sandy flats, edges of playas, gravelly washes, riverbanks
Elevation: 70–1000 m

Distribution

V20-921-distribution-map.gif

Ariz., Calif., Nev., Mexico (Sonora)

Discussion

Arida arizonica is a widespread and variable species recognized by its annual habit, deeply lobed or pinnatifid leaves, dense glandularity, relatively small heads with lavender to whitish ray florets, and absence of pappi on the ray florets.

Selected References

None.

Lower Taxa

None.

... more about "Arida arizonica"
not tailed +, rounded +  and obtuse +
spiny-tipped +
purplish;green +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
corymbiform +  and leafy +
indeterminate +  and determinate +
Ronald L. Hartman +  and David J. Bogler +
(R. C. Jackson & R. R. Johnson) D. R. Morgan & R. L. Hartman +
linear +  and lanceolate oblanceolate or obovate +
decurrent +
indurate to herbaceous +
Machaeranthera arizonica +
compound +  and simple +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
oblanceolate;oblong +
reduced +
1mm;25mm +
rugulose +  and muricate +
barbellulate +  and barbellate +
attenuate +
lanceolate +  and scalelike +
Desert tansy-aster +
not 2-lipped +  and actinomorphic +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
oblanceolate +
fertile +  and bisexual +
fertile +  and bisexual +
equaling +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Ariz. +, Calif. +, Nev. +  and Mexico (Sonora) +
70–1000 m +
sericeous +  and glandular-hispidulous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Dry, open sandy flats, edges of playas, gravelly washes, riverbanks +
discoid +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
hemispheric +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
lavender +  and whitish +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
triangular +
pinnatifid +  and dentate +
2-carpellate +
whitish +  and white +
persistent +
Flowering Mar–Nov. +
appressed +  and reflexed +
lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
Illustrated +
gland-dotted +
erect +  and ascending +
2 +  and 6 +
slender +
appendaged +  and truncate +
papillate +  and smooth +
Machaeranthera ammophila +, Machaeranthera arida +  and Machaeranthera coulteri var. arida +
Arida arizonica +
species +
1/4-1/2 times funnelform throats +
rhizomatous +  and taprooted +
60 cm600 mm <br />0.6 m <br /> (90 cm900 mm <br />0.9 m <br />) +
5 cm50 mm <br />0.05 m <br /> (40 cm400 mm <br />0.4 m <br />) +