Euphorbia abramsiana |
Euphorbia curtisii |
|
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Abrams' sandmat, Abrams' spurge |
Curtis' spurge, Sandhills spurge |
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Habit | Herbs, annual, with slender taproot. | Herbs, perennial, with spreading rootstock. |
Stems | prostrate, mat-forming, 10–35(–50) cm, shortly pilose or puberulent at least proximally, often glabrous distally. |
erect or ascending, branched, solitary or few, previous year's dead stems not persistent, 20–40 cm, usually glabrous, rarely strigose to sericeous at nodes. |
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. |
alternate; stipules to 0.1 mm; petiole to (0–)1–2 mm, glabrous or strigose to sericeous; blade usually linear, occasionally elliptic, rarely ovate, proximal often greatly reduced and often scalelike, 10–30 × 1.5–6 mm, base cuneate, margins entire, occasionally sparsely ciliate, apex rounded or broadly acute, abaxial surface glabrous or sparsely strigose to sericeous, adaxial surface glabrous; venation obscure, 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. |
campanulate, 1–1.2 × 1.3–1.5(–1.7) mm, glabrous or strigose to sericeous on distal 1/2; glands 5, green, reniform, 0.3 × 0.6 mm; appendages white, semicircular, 0.3–0.4 × 0.6–0.8 mm, entire. |
Staminate flowers | 3–5. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.1–0.3 mm, 2-fid nearly entire length. |
ovary glabrous or sparsely strigose to sericeous; styles 0.6–1.1 mm, 2-fid at apex to 1/2 length. |
Capsules | ellipsoid to ovoid, 1.3–1.5 × 1.1–1.5 mm, glabrous; columella 1–1.3 mm. |
globose, 2.5–3.2 × 4.3–5.1 mm, glabrous or sparsely strigose to sericeous; columella 2.4–3.1 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. |
usually gray to black, occasionally brown, ovoid-globose, 2.2 × 1.8 mm, smooth; caruncle absent. |
Cyathia | solitary at distal nodes of primary stems or at nodes of short congested axillary branchlets; peduncle 0.2–0.5 mm. |
in terminal pleiochasia (fertile axillary branches occasionally present); peduncle 6.5–17 mm, filiform, glabrous. |
Euphorbia abramsiana |
Euphorbia curtisii |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting early spring–summer. |
Habitat | Desert scrub and desert grasslands. | Xeric to dry oak or oak-pine scrub of sand hills, pine-oak woodlands, pine-oak savannas. |
Elevation | -40–1400 m. (-100–4600 ft.) | 0–200 m. (0–700 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Sonora)
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FL; GA; NC; SC
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Discussion | Euphorbia curtisii is found in the Gulf and Atlantic coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 259. | FNA vol. 12, p. 245. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Chamaesyce abramsiana | E. eriogonoides, Tithymalopsis curtisii, T. eriogonoides |
Name authority | L. C. Wheeler: Bull. S. Calif. Acad. Sci. 33: 109. (1934) | Engelmann ex Chapman: Fl. South. U.S., 401. (1860) |
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