Euphorbia micromera

Boissier

Proc. Amer. Acad. Arts 5: 171. 1861.

Common names: Desert spurge Sonoran or tiny sandmat
Weedy
Synonyms: Chamaesyce micromera (Boissier) Wooton & Standley
Treatment appears in FNA Volume 12. Treatment on page 278. Mentioned on page 254, 258, 270, 281.

Herbs, annual, with slender taproot. Stems prostrate, mat-forming, 5–35 cm, glabrous or shortly pilose. Leaves opposite; stipules distinct, subulate, 0.2–0.4 mm, pilose; petiole 0.5–1.2 mm, glabrous or pilose; blade ovate to elliptic, 6–15 × 2–4 mm, base asymmetric, one side cuneate to rounded, other side rounded, margins entire, apex obtuse, surfaces glabrous or pilose; venation obscure or only midvein conspicuous. Cyathia solitary at distal nodes; peduncle 0.4–1.4 mm. Involucre campanulate, 0.4–0.6 × 0.5–0.9 mm, glabrous or pilose; glands 4, red, circular to oblong, 0.1 × 0.1–0.2 mm; appendages absent. Staminate flowers 2–5. Pistillate flowers: ovary usually glabrous, rarely pilose; styles 0.1–0.2 mm, 2-fid at apex. Capsules oblong, 1.3–1.5 × 1.1–1.3 mm, usually glabrous, rarely pilose; columella 1–1.2 mm. Seeds light gray, narrowly ovoid, 4-angled in cross-section, 0.9–1 × 0.5–0.6 mm, smooth to slightly rugose or with 1–4 faint transverse ridges that do not pass through abaxial keel.


Phenology: Flowering nearly year-round in response to sufficient rainfall.
Habitat: Desert scrub, riparian woods with ash and willow, saltbush scrub, Joshua tree woodlands and grasslands, often in sandy or gravelly areas.
Elevation: -20–1800 m.

Distribution

V12 964-distribution-map.jpg

Ariz., Calif., Nev., N.Mex., Tex., Utah, Mexico (Baja California), Mexico (Baja California Sur), Mexico (Chihuahua), Mexico (Coahuila), Mexico (Durango), Mexico (Sonora)

Discussion

Selected References

None.

Lower Taxa

None.

"connate" is not a number. "distinct" is not a number."connate" is not a number. "distinct" is not a number.

... more about "Euphorbia micromera"
Victor W. Steinmann +, Jeffery J. Morawetz +, Paul E. Berry +, Jess A. Peirson +  and Ya Yang +
Boissier +
Anisophyllum +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
ovate;elliptic +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
pilose +  and glabrous +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Desert spurge +  and Sonoran or tiny sandmat +
Ariz. +, Calif. +, Nev. +, N.Mex. +, Tex. +, Utah +, Mexico (Baja California) +, Mexico (Baja California Sur) +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Durango) +  and Mexico (Sonora) +
-20–1800 m. +
pistillate +  and staminate +
subtending +
circular +  and oblong +
0.1mm +  and 0.2mm +
Desert scrub, riparian woods with ash and willow, saltbush scrub, Joshua tree woodlands and grasslands, often in sandy or gravelly areas. +
axillary +  and terminal +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
pilose +  and glabrous +
campanulate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
caducous +, deciduous +  and persistent +
bractlike +
palmate +  and pinnate +
toothed +  and entire +
pilose;glabrous +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
connate;distinct +
pilose +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Flowering nearly year-round in response to sufficient rainfall. +
Proc. Amer. Acad. Arts +
1 +  and 4 +
light gray +
4-angled +  and ovoid +
rounded +  and cuneate +
free +, connate +  and distinct +
mat-forming +
decumbent +, reclining +, ascending +  and erect +
pilose +  and glabrous +
flattened +  and terete +
5 cm50 mm <br />0.05 m <br /> (35 cm350 mm <br />0.35 m <br />) +
interpetiolar +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
connate +  and distinct +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (?) +  and 0.02 cm0.2 mm <br />2.0e-4 m <br /> (?) +
pilose +  and glabrous +
Chamaesyce micromera +
Euphorbia micromera +
Euphorbia sect. Anisophyllum +
species +
axillary +  and terminal +
10 +, 9 +, 8 +, 7 +  and 6 +