Euphorbia platysperma

Engelmann in W. H. Brewer et al.

Bot. California 2: 482. 1880.

Common names: Dune or flat-seeded spurge flatseed sandmat
Conservation concern
Synonyms: Chamaesyce platysperma (Engelmann) Shinners
Treatment appears in FNA Volume 12. Treatment on page 282. Mentioned on page 257.

Herbs, annual or short-lived perennial, with slender taproot. Stems prostrate, spreading and often mat-forming, 10–100 cm, glabrous. Leaves opposite; stipules usually distinct, occasionally connate basally, rarely to middle, subulate, narrowly triangular, or divided into 2–4 subulate segments, 0.5–1.1 mm, glabrous; petiole 1–3.6 mm, glabrous; blade oblong to obovate, 5–12 × 3–5 mm, base subsymmetric, cuneate to attenuate, margins entire, apex usually acute to mucronulate, rarely obtuse, surfaces glabrous; only midvein conspicuous. Cyathia solitary at distal nodes; peduncle 1.6–4.1 mm. Involucre campanulate to obconic, 1.5–2 × 1.3–2.5 mm, glabrous; glands 4, yellowish, subcircular to oblong, 0.5–0.6 × 0.5–0.6 mm; appendages white, ovate to oblong or almost triangular, 0.3–0.6 × 0.3–0.8 mm, distal margin entire or shallowly 2–3-lobed. Staminate flowers 45–50. Pistillate flowers: ovary glabrous, styles 0.4–0.6 mm, 2-fid 1/2 length. Capsules ovoid to ellipsoid, 2.7–3.2 × 2.2–2.9 mm, glabrous; columella 2.6–2.8 mm. Seeds whitish, pinkish, or light-brown, ellipsoid-oblong, weakly dorsiventrally compressed and semielliptic in cross-section, 2.2–2.5 × 1.3–1.6 mm, with sharp linelike longitudinal ridge on adaxial side, smooth and rounded on back.


Phenology: Flowering and fruiting year-round in response to sufficient moisture.
Habitat: Sand dunes in Sonoran Desert scrub.
Elevation: 60–200 m.

Distribution

V12 814-distribution-map.jpg

Ariz., Calif., Mexico (Baja California), Mexico (Sonora)

Discussion

Selected References

None.

Lower Taxa

None.

"connate" is not a number. "distinct" is not a number."/2" is not declared as a valid unit of measurement for this property.

... more about "Euphorbia platysperma"
obtuse;usually acute;mucronulate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
triangular +, ovate +  and oblong +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
Engelmann in W. H. Brewer et al. +
subsymmetric +
pinnate +, symmetric +  and asymmetric +
cuneate +  and attenuate +
Anisophyllum +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
oblong;obovate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
ovoid +  and ellipsoid +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
Dune or flat-seeded spurge +  and flatseed sandmat +
2-3-lobed +  and entire +
Ariz. +, Calif. +, Mexico (Baja California) +  and Mexico (Sonora) +
60–200 m. +
pistillate +  and staminate +
0.5mm;0.6mm +
subtending +
subcircular +  and oblong +
0.5mm +  and 0.6mm +
Sand dunes in Sonoran Desert scrub. +
axillary +  and terminal +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
campanulate +  and obconic +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
caducous +, deciduous +  and persistent +
bractlike +
palmate +  and pinnate +
toothed +  and entire +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.41 cm4.1 mm <br />0.0041 m <br />) +
connate;distinct +
0.1 cm1 mm <br />0.001 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
Flowering and fruiting year-round in response to sufficient moisture. +
Bot. California +
linelike +  and sharp +
light-brown;pinkish;light-brown;pinkish;whitish +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
rounded +, compressed +  and ellipsoid-oblong +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
Conservation concern +
free +, connate +  and distinct +
mat-forming +
flattened +  and terete +
10 cm100 mm <br />0.1 m <br /> (100 cm1,000 mm <br />1 m <br />) +
connate +  and distinct +
interpetiolar +
divided +, triangular +  and subulate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
connate +  and distinct +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (?) +  and 0.06 cm0.6 mm <br />6.0e-4 m <br /> (?) +
Chamaesyce platysperma +
Euphorbia platysperma +
Euphorbia sect. Anisophyllum +
species +
axillary +  and terminal +
perennial +, short-lived +  and annual +
10 +, 9 +, 8 +, 7 +  and 6 +