Euphorbia abramsiana |
Euphorbia gracillima |
|
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Abrams' sandmat, Abrams' spurge |
Mexican sandmat |
|
Habit | Herbs, annual, with slender taproot. | Herbs, annual, with slender taproot. |
Stems | prostrate, mat-forming, 10–35(–50) cm, shortly pilose or puberulent at least proximally, often glabrous distally. |
erect to ascending, 5–25 cm, glabrous. |
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 distinct, subulate-filiform, entire, 0.3–0.5 mm, glabrous; petiole 0.4–0.9 mm, glabrous; blade narrowly oblong to linear, often slightly falcate, 2–15 × 0.3–0.8 mm, base symmetric to subsymmetric, rounded to attenuate, margins entire, thickened and often revolute, apex acute to obtuse, surfaces glabrous; only midvein conspicuous. |
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. |
turbinate, 0.4–0.5 × 0.4–0.6 mm, glabrous; glands 4, yellow to pink, oblong to slightly reniform, (0–)0.1–1 × 0.1–0.2 mm; appendages white to pink, ovate to oblong, 0.2–0.4 × 0.1–0.3 mm, distal margin usually entire, rarely emarginate. |
Staminate flowers | 3–5. |
5–12. |
Pistillate flowers | ovary glabrous; styles 0.1–0.3 mm, 2-fid nearly entire length. |
ovary glabrous; styles 0.1–0.2 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. |
broadly ovoid, 1.1–1.4 mm diam., glabrous; columella 0.8–1.1 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. |
orange to tan or reddish brown, narrowly ovoid, 4-angled in cross section, 0.9–1.1 × 0.5–0.6 mm, smooth. |
Cyathia | solitary at distal nodes of primary stems or at nodes of short congested axillary branchlets; peduncle 0.2–0.5 mm. |
solitary at distal nodes; peduncle 0.1–0.9 mm. |
Euphorbia abramsiana |
Euphorbia gracillima |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting late summer–fall. |
Habitat | Desert scrub and desert grasslands. | Rocky slopes and dry washes in desert scrub. |
Elevation | -40–1400 m. (-100–4600 ft.) | 600–900 m. (2000–3000 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Sonora)
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AZ; Mexico (Chihuahua, Jalisco, Sinaloa, Sonora) |
Discussion | Euphorbia gracillima occurs from south-central Arizona (Pima and Pinal counties) south through northwestern Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 259. | FNA vol. 12, p. 270. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce abramsiana | Chamaesyce gracillima |
Name authority | L. C. Wheeler: Bull. S. Calif. Acad. Sci. 33: 109. (1934) | S. Watson: Proc. Amer. Acad. Arts 21: 438. (1886) |
Web links |