Arida parviflora

(A. Gray) D. R. Morgan & R. L. Hartman

Sida 20: 1414. 2003.

Common names: Small-flower tansy-aster
Basionyms: Machaeranthera parviflora A. Gray Smithsonian Contr. Knowl. 3(5): 90. 1852
Treatment appears in FNA Volume 20. Treatment on page 405. Mentioned on page 402.

Annuals or short-lived perennials, 10–50 cm; taproots slender to ± thickened. Stems 1–15+, mostly erect to ascending, rarely reclining, slender, much branched distally or throughout, glaucous, glabrous or sparsely gland-dotted from midstem distally. Leaves mostly cauline; sessile; blades lanceolate to oblong, reduced distally, 10–30 × 2–7 mm, bases often clasping, margins shallowly or deeply pinnatifid to 2-pinnatifid, toothed, or entire, apices apiculate to rounded, faces glabrous to sparsely stipitate-glandular; distal ascending to appressed. Heads borne singly (terminal), in loose, leafy, corymbiform arrays. Involucres hemispheric, 3–5 × 4–6 mm (fresh). Phyllaries in 3–4 series, ± appressed, lanceolate to oblanceolate, 1–4 mm, bases whitish, margins ± entire, apices green or purple, mostly acute, minutely glandular. Ray-florets 10–30+; laminae violet-blue to lavender, rarely whitish, 6–8 mm, coiled after flowering. Disc-florets 18–40+; corollas yellow, 4–5 mm. Cypselae oblanceolate, 1.5–2 mm, 8–10 per face, faces moderately sericeous; pappi setose; ray 0 or white, 1–1.5 mm; disc whitish, 4–5.5 mm. 2n = 10.


Phenology: Flowering Jul–Oct.
Habitat: Saline flats, playas, swales, sandy areas, river margins
Elevation: 1100–1700 m

Distribution

V20-925-distribution-map.gif

Ariz., Colo., N.Mex., Tex., Utah, Mexico (Chihuahua), Mexico (Coahuila)

Discussion

Arida parviflora is recognized by its wiry stems, small, deeply pinnatifid leaves, rather small involucres, and ray cypselae usually with pappi. This species is often described as being an annual; however, some specimens have a large, woody root and well-developed branching crown like a perennial plant.

Selected References

None.

Lower Taxa

None.

... more about "Arida parviflora"
not tailed +, rounded +  and obtuse +
purple;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 +
(A. Gray) D. R. Morgan & R. L. Hartman +
linear +  and lanceolate oblanceolate or obovate +
decurrent +
indurate to herbaceous +
Machaeranthera parviflora +
compound +  and simple +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
lanceolate;oblong +
reduced +
2mm;7mm +
rugulose +  and muricate +
barbellulate +  and barbellate +
attenuate +
lanceolate +  and scalelike +
Small-flower tansy-aster +
not 2-lipped +  and actinomorphic +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
8 +  and 10 +
oblanceolate +
fertile +  and bisexual +
fertile +  and bisexual +
equaling +
compressed +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
ascending;appressed +
Ariz. +, Colo. +, N.Mex. +, Tex. +, Utah +, Mexico (Chihuahua) +  and Mexico (Coahuila) +
1100–1700 m +
sericeous +, glabrous +  and sparsely stipitate-glandular +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Saline flats, playas, swales, sandy areas, river margins +
discoid +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
hemispheric +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
whitish +, violet-blue +  and lavender +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
triangular +
toothed +, pinnatifid +  and 2-pinnatifid +
2-carpellate +
whitish +  and white +
persistent +
Flowering Jul–Oct. +
reflexed +, spreading +  and appressed +
lanceolate +  and oblanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
gland-dotted +
reclining +, mostly erect +  and ascending +
1 +  and 15 +
slender +
appendaged +  and truncate +
papillate +  and smooth +
Compositae +
Arida parviflora +
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 />) +
perennial +, short-lived +  and annual +
10 cm100 mm <br />0.1 m <br /> (50 cm500 mm <br />0.5 m <br />) +