Euphorbia abramsiana |
Euphorbia mendezii |
|
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Abrams' sandmat, Abrams' spurge |
Mendez's sandmat |
|
Habit | Herbs, annual, with slender taproot. | Herbs, annual or perennial, with slender taproot. |
Stems | prostrate, mat-forming, 10–35(–50) cm, shortly pilose or puberulent at least proximally, often glabrous distally. |
prostrate, often mat-forming, 8–35 cm, usually villous along margins, lower surface glabrous, upper surface usually strigillose to puberulent, rarely glabrous or glabrate. |
Leaves | opposite; stipules distinct, divided into 5–7 subulate-filiform segments, 0.6–1.1 mm, usually glabrous, rarely pilose; petiole 0.5–1 mm, glabrous; blade ovate, elliptic-oblong, or slightly ovate-cordate, 3–11 × 2–5 mm, base asymmetric, truncate to hemicordate, margins serrulate at least toward apex, often entire toward base, apex acute to obtuse, surfaces sometimes with red spot in center, glabrous; usually only the midvein conspicuous. |
opposite; stipules usually distinct or connate basally, rarely completely connate, deltate, laciniate, glabrous or pilose (lower side), forming narrow deltate scale, sometimes apically 2-fid or laciniate, glabrous (upper side), 0.4–1.9 mm; petiole 0.3–1.2 mm, glabrous, pilose or villous; blade oblong to obovate, 4–12 × 2–7 mm, base asymmetric, one side attenuate, cuneate or rounded, other rounded or cordate, margins serrulate at least distally, apex obtuse, surfaces glabrous or sparsely sericeous, pilose or villous; 3-veined at base. |
Involucre | obconic, 0.5–0.6 × 0.4–0.5 mm, glabrous; glands 4, yellowish to pink, circular to oblong, 0.1 × 0.1–0.2 mm; appendages absent, or white to pink, semicircular to broadly ovate, to 0.1 × 0.2 mm, distal margin entire or shallowly lobed. |
campanulate or obconic, 0.8–1 × 0.7–0.8 mm, usually glabrous, rarely sparsely pilose toward apex; glands 4, pink, reniform, oblong or elliptic, 0.1 × 0.2–0.3 mm; appendages absent or white to pink, oblong, flabellate or forming narrow rim around edge of gland, 0.1–0.3 × 0.3–0.6 mm, distal margin usually entire, sometimes lobed. |
Staminate flowers | 3–5. |
6–15. |
Pistillate flowers | ovary glabrous; styles 0.1–0.3 mm, 2-fid nearly entire length. |
ovary usually pilose or villous with hairs concentrated along keels, rarely glabrous; styles 0.2–0.3 mm, 2-fid 1/2 length. |
Capsules | ellipsoid to ovoid, 1.3–1.5 × 1.1–1.5 mm, glabrous; columella 1–1.3 mm. |
ovoid, 1.2–1.6 × 1.2–1.4 mm, usually pilose or villous with hairs concentrated along keels, often glabrous in between, very rarely completely glabrous; columella 1–1.4 mm. |
Seeds | light gray to light brown, narrowly ovoid to ovoid, 4-angled in cross section, 1–1.2 × 0.6–0.7 mm, with 3–5 prominent transverse ridges that often interrupt abaxial keel. |
reddish brown to orange or gray-pink, narrowly ovoid, 4-angled in cross section, 0.9–1.2 × 0.5–0.6 mm, almost smooth or with 5–7 faint transverse ridges that do not pass through abaxial keel. |
Cyathia | solitary at distal nodes of primary stems or at nodes of short congested axillary branchlets; peduncle 0.2–0.5 mm. |
solitary at nodes or on short, congested axillary branches; peduncle 0.9–2.5 mm. |
Euphorbia abramsiana |
Euphorbia mendezii |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting year-round. |
Habitat | Desert scrub and desert grasslands. | Disturbed areas. |
Elevation | -40–1400 m. (-100–4600 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Sonora)
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FL; Mexico; Central America; West Indies; n South America [Introduced in North America] |
Discussion | Euphorbia mendezii is a common weed distributed widely throughout Mexico and Central America. Within the flora area the species is known only from southern Florida. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 259. | FNA vol. 12, p. 277. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce abramsiana | Chamaesyce mendezii |
Name authority | L. C. Wheeler: Bull. S. Calif. Acad. Sci. 33: 109. (1934) | Boissier: Cent. Euphorb., 15. (1860) |
Web links |