Malacothrix sonchoides

(Nuttall) Torrey & A. Gray

Fl. N. Amer. 2: 486. 1843.

Common names: Sow-thistle desertdandelion
IllustratedEndemic
Basionym: Leptoseris sonchoides Nuttall Trans. Amer. Philos. Soc., n. s. 7: 439. 1841
Synonyms: Malacothrix runcinata A. Nelson
Treatment appears in FNA Volume 19. Treatment on page 320. Mentioned on page 311, 312.

Annuals, (5–) 10–25 (–50) cm. Stems 1–5, ascending to erect, branched near bases and distally, usually glabrous (sometimes glaucous), rarely stipitate-glandular. Cauline leaves: proximal narrowly oblong to elliptic, pinnately lobed (lobes 3–8+ pairs, oblong to triangular, ± equal, apices obtuse to acute), ± fleshy, ultimate margins dentate to denticulate, faces glabrous; distal reduced (narrowly triangular to linear, bases ± dilated, ± clasping). Calyculi of 8–12+, ovate to lanceolate bractlets, hyaline margins 0.05–0.3 (–0.7) mm wide, usually glabrous (margins sometimes stipitate-glandular). Involucres ± campanulate to hemispheric, 7–13 × 4–6 (–12+) mm. Receptacles bristly. Florets 75–115; corollas lemon yellow, 10–14 (–16) mm; outer ligules exserted 6–10 (–13) mm. Cypselae ± cylindro-fusiform to prismatic, 1.8–3 mm, ribs extending to apices, ± equal or 5 more prominent than others; pappi persistent, crenate crowns of 15–25+, blunt or rounded teeth. Pollen 70–100% 3-porate. 2n = 14.


Phenology: Flowering Mar–Jun.
Habitat: Usually on dunes or in deep, fine sand in arroyos and on plains in Joshua tree woodlands, grasslands, Ephedra-Coleogyne associations
Elevation: 300–2100 m

Distribution

V19-486-distribution-map.gif

Ariz., Calif., Colo., Nev., N.Mex., Utah, Wyo.

Discussion

Malacothrix sonchoides grows in California in the Mojave Desert (Los Angeles, Kern, San Bernardino, and Riverside counties), the Great Basin Desert (Inyo Mountains), and barely enters the northern margins of the Sonoran Desert. It also grows in the Intermountain Region in Arizona, Colorado, Nevada, New Mexico, Utah, and Wyoming.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."]" is not declared as a valid unit of measurement for this property.

... more about "Malacothrix sonchoides"
obtuse;acute or acuminate +
scarious +
ovate +  and lanceolate +
corymbiform +  and paniculiform +
indeterminate +  and determinate +
W. S. Davis +
(Nuttall) Torrey & A. Gray +
decurrent +
Leptoseris sonchoides +
compound +  and simple +
lanceolate;obovate oblanceolate or spatulate +
tuberculate +, rugose +, muricate +  and smooth +
ovate;lanceolate +
subequal +  and unequal +
filiform +
Sow-thistle desertdandelion +
zygomorphic +, actinomorphic +  and (3-)5-merous +
1.4 cm14 mm <br />0.014 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
lemon yellow +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
crenate +
stramineous +  and brown or purplish brown +
less cylindro-fusiform +  and prismatic +
Ariz. +, Calif. +, Colo. +, Nev. +, N.Mex. +, Utah +  and Wyo. +
300–2100 m +
winged +  and beaked +
dispersed +
Usually on dunes or in deep, fine sand in arroyos and on plains in Joshua tree woodlands, grasslands, Ephedra-Coleogyne associations +
indeterminate +
each +  and sessile +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
less campanulate;hemispheric +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
cauline +  and basal +
divided +, lobed +  and dentate +
0.05mm +  and 0.3mm +
1 cm10 mm <br />0.01 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
2-carpellate +
persistent +
Flowering Mar–Jun. +
connate +  and distinct +
12 +  and 25 +
subequal +  and unequal +
Fl. N. Amer. +
flat;more or less convex +
more or less equal or 5 more prominent +
crenate +
exalbuminous +
Illustrated +  and Endemic +
ascending +  and erect +
stipitate-glandular +  and glabrous +
1 +  and 5 +
appendaged +  and truncate +
papillate +
Malacothrix runcinata +
Malacothrix sonchoides +
Malacothrix +
species +
rounded +  and blunt +
dentate +  and denticulate +
25 cm250 mm <br />0.25 m <br /> (50 cm500 mm <br />0.5 m <br />) +
10 cm100 mm <br />0.1 m <br /> (25 cm250 mm <br />0.25 m <br />) +
shrub +  and subshrub +