Malacothrix sonchoides

(Nuttall) Torrey & A. Gray

Fl. N. Amer. 2: 486. 1843

Common names: Sow-thistle desertdandelion
Basionyms: 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



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


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.



Lower Taxa

No lower taxa listed.

AuthorW. S. Davis +
Authority(Nuttall) Torrey & A. Gray +
BasionymsLeptoseris sonchoides +
Common nameSow-thistle desertdandelion +
DistributionAriz. +, Calif. +, Colo. +, Nev. +, N.Mex. +, Utah + and Wyo. +
Elevation300–2100 m +
HabitatUsually on dunes or in deep, fine sand in arroyos and on plains in Joshua tree woodlands, grasslands, Ephedra-Coleogyne associations +
IllustratorYevonn Wilson-Ramsey +
PhenologyFlowering Mar–Jun. +
Publication titleFl. N. Amer. +
Publication year1843 +
ReferenceNone +
Source xml grained fna xml/V19-20-21/V19 486.xml +
SynonymsMalacothrix runcinata +
Taxon familyAsteraceae +
Taxon nameMalacothrix sonchoides +
Taxon parentMalacothrix +
Taxon rankspecies +
VolumeVolume 19 +