Euphorbia vallis-mortae

(Millspaugh) J. T. Howell

Madroño 2: 19. 1931.

Common names: Death Valley sandmat
Basionym: Chamaesyce vallis-mortae Millspaugh Publ. Field Mus. Nat. Hist., Bot. Ser. 2: 403. 1916
Treatment appears in FNA Volume 12. Treatment on page 291. Mentioned on page 254, 292.

Herbs, perennial, with thickened, woody taproot. Stems prostrate to ascending, often mat-forming, 10–45 cm, pilose to villous. Leaves opposite; stipules distinct or connate, subulate to filiform, 0.4–1.1 mm, densely tomentose; petiole 0.4–1 mm, pilose to villous; blade suborbiculate to oblong-ovate, 3–8 × 2–6 mm, base slightly asymmetric, rounded, margins entire, apex rounded to obtuse, surfaces pilose to villous; 3-veined at base, midvein conspicuous, venation often obscured by pubescence. Cyathia solitary at distal nodes; peduncle 0.5–1.8 mm. Involucre obconic-campanulate, 1.2–2.3 × 1–1.8 mm, densely pilose to villous; glands 4, yellow to red, subcircular to oblong, 0.2–0.5 × 0.4–0.9 mm; appendages white, flabellate to oblong, 0.1–0.7 × 0.5–1.9 mm, distal margin entire or crenulate, adaxial surface ciliate-puberulent. Staminate flowers 15–22(–50). Pistillate flowers: ovary densely pilose; styles 0.4–0.8 mm, 2-fid 1/2 length. Capsules ovoid, 1.5–2.2 × 1.8–2.2 mm, tomentose; columella 1.2–1.6 mm. Seeds white, gray, or light brown, ovoid, sharply 4-angled in cross section, abaxial faces slightly convex, adaxial faces concave, 1.2–1.7 × 0.6–0.9 mm, smooth.

Phenology: Flowering and fruiting late spring–fall.
Habitat: Roadsides, desert scrub, streamsides, sandy washes.
Elevation: 700–2000 m.


The specific epithet of Euphorbia vallis-mortae is a misnomer because the species does not occur in Death Valley; instead, it is found at the transition of the northern edge of the Mojave Desert and the foothills of the southern Sierra Nevada in Inyo, Kern, and San Bernardino counties.

Selected References


Lower Taxa

... more about "Euphorbia vallis-mortae"
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
(Millspaugh) J. T. Howell +
Chamaesyce vallis-mortae +
Death Valley sandmat +
700–2000 m. +
Roadsides, desert scrub, streamsides, sandy washes. +
Flowering and fruiting late spring–fall. +
Chamaesyce +
Euphorbia vallis-mortae +
Euphorbia sect. Anisophyllum +
species +