Euphorbia abramsiana |
Euphorbia serrata |
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Abrams' sandmat, Abrams' spurge |
saw tooth spurge, saw-tooth or tooth or serrate spurge, serrate spurge |
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Habit | Herbs, annual, with slender taproot. | Herbs, perennial, with thick rootstock. |
Stems | prostrate, mat-forming, 10–35(–50) cm, shortly pilose or puberulent at least proximally, often glabrous distally. |
erect, branched, 10–70 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. |
petiole absent; blade lanceolate, ovate-lanceolate, linear, or linear-lanceolate, 10–70 × 2–20 mm, base acute or obtuse, margins irregularly serrate, apex acute to obtuse, surfaces glabrous; venation inconspicuous, only midvein prominent. |
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, 2–4 × 1.2–3 mm, glabrous; glands 4–5, elliptic, ovate, or suborbiculate, 1.2–1.8 × 1.5–2.7 mm; horns absent or slightly divergent, 0–0.6 mm. |
Staminate flowers | 3–5. |
20–40. |
Pistillate flowers | ovary glabrous; styles 0.1–0.3 mm, 2-fid nearly entire length. |
ovary glabrous; styles 1–2 mm, 2-fid. |
Capsules | ellipsoid to ovoid, 1.3–1.5 × 1.1–1.5 mm, glabrous; columella 1–1.3 mm. |
subovoid, 4.5–6 × 4–5 mm, 3-lobed; cocci rounded, smooth occasionally slightly puncticulate, glabrous; columella 4–4.5 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. |
grayish, cylindric, 2.5–3.1 × 1.7–2 mm, smooth or slightly dotted; caruncle subconic, lobed, 1–1.5 × 0.5–1 mm. |
Cyathia | solitary at distal nodes of primary stems or at nodes of short congested axillary branchlets; peduncle 0.2–0.5 mm. |
peduncle 1–5 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 1–3 times 2-branched; pleiochasial bracts ovate-lanceolate, usually shorter and wider than distal leaves; dichasial bracts distinct, ovate or deltate, base obtuse to cordate, margins irregularly dentate, apex acute, or obtuse, mucronate; axillary cymose branches 0–3. |
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Euphorbia abramsiana |
Euphorbia serrata |
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Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting spring–fall. |
Habitat | Desert scrub and desert grasslands. | Waste places, disturbed sites, roadsides, fields, pastures. |
Elevation | -40–1400 m. (-100–4600 ft.) | 0–300 m. (0–1000 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Sonora)
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CA; Europe; Atlantic Islands (Macaronesia) [Introduced in North America] |
Discussion | Euphorbia serrata, native to the western Mediterranean region of Europe and Macaronesia, is listed as a noxious weed by the state of California. In the flora area, it has been found in coastal counties from Sonoma to Monterey counties; attempts to eradicate it may have been successful. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 259. | FNA vol. 12, p. 309. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce abramsiana | Galarhoeus serratus, Tithymalus serratus |
Name authority | L. C. Wheeler: Bull. S. Calif. Acad. Sci. 33: 109. (1934) | Linnaeus: Sp. Pl. 1: 459. (1753) |
Web links |