Euphorbia graminea |
Euphorbia lata |
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grassleaf spurge |
broadleaf spurge, hoary sandmat |
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Habit | Herbs, usually annual, rarely perennial, with slender, rarely tuberous, taproot. | Herbs, perennial, with moderately thickened to robust rootstock. |
Stems | erect or ascending, branched, 30–80(–110) cm, strigillose or glabrescent, sharply angled. |
ascending to erect, or prostrate, 10–25 cm, strigose to short-sericeous or ± villous. |
Leaves | usually alternate, sometimes some opposite; stipules usually 0.2–0.5 mm, rarely rudimentary; petiole 0.4–5.9 mm, strigillose; blade ovate, elliptic, linear-elliptic, or oblong, 10–83 × 3–39 mm, base attenuate, rounded, or cuneate, margins entire, apex acute or obtuse, surfaces strigillose; venation occasionally obscure on narrow leaves, midvein conspicuous. |
opposite; stipules distinct, filiform, 0.8–1.3 mm, strigose to short-sericeous or ± villous; petiole 0.5–2 mm, densely strigose to short-sericeous or ± villous; blade narrowly to broadly ovate-deltate, older ones often falcate, 4–12 × 3–7 mm, base asymmetric, obliquely rounded to obtuse, noticeably wider on one side, margins entire, often ± revolute, apex broadly acute, surfaces strigose to short-sericeous or ± villous; obscurely 3–5-veined from base, midvein prominent abaxially. |
Involucre | campanulate or obconic, 1–1.8 × 0.8–1.7 mm, glabrous or strigillose toward rim; glands (1–)2–4, yellow to greenish, elliptic or oblong, 0.1–0.3 × 0.2–0.4 mm; appendages white to tinged purple, ovate and often hoodlike or forming narrow rim around distal margin of gland, 0.3–1.6 × 0.4–0.9 mm, entire. |
broadly campanulate, 2–2.5 × 2.2–2.6, strigose; glands 4, greenish, oblong to semilunate, 0.2–0.7 × 0.6–1 mm; appendages rudimentary or white, forming narrow band, (0–)0.1–0.2 × (0–)0.6–1 mm, distal margin entire or crenate. |
Staminate flowers | 30–40. |
25–35. |
Pistillate flowers | ovary glabrous; styles 0.7–1 mm, 2-fid from 1/2 to nearly entire length. |
ovary densely strigose to short-sericeous or ± villous; styles dark purplish, 0.8–1.2 mm, 2-fid 1/2 to nearly entire length. |
Capsules | ovoid-oblate, 2.5–3 × 3–3.5 mm, glabrous; columella 1.6–1.9 mm. |
ovoid, 1.9–2.3 × 2–2.4 mm, strigose to short-sericeous or ± villous; columella 1.7–2.2 mm. |
Seeds | gray, brown, or nearly black, ovoid, circular or weakly angled in cross section, 1.5–1.7 × 1.3–1.5 mm, coarsely tuberculate with longitudinal rows of shallow pits; caruncle absent or punctiform, 0.1–0.2 mm. |
whitish, oblong, 4-angled in cross section, faces concave, 1.5–1.8(–2) × 0.6–0.9 mm, smooth. |
Cyathia | in usually terminal, rarely axillary, dichasia, distal dichasial bracts often white; peduncle 0.4–4.5 mm (to 15 mm at first node of inflorescence), glabrous. |
solitary at distal nodes; peduncle 1–3 mm. |
2n | = 28, 56. |
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Euphorbia graminea |
Euphorbia lata |
|
Phenology | Flowering and fruiting year-round. | Flowering and fruiting spring–fall. |
Habitat | Disturbed, weedy, or urban areas. | Mountain slopes, canyons, basins, rocky prairies, roadsides, disturbed sites, usually in calcareous soils, sometimes in igneous-derived, sandy or rocky soils. |
Elevation | 0–500 m. (0–1600 ft.) | 600–2200 m. (2000–7200 ft.) |
Distribution |
AR; CA; FL; LA; TX; Mexico; Central America; South America [Introduced in North America; introduced also in West Indies, Asia, Pacific Islands]
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CO; KS; NM; OK; TX; Mexico (Chihuahua, Coahuila)
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Discussion | Euphorbia graminea occurs natively from northern South America to northern Mexico. The species is a variable and taxonomically complex entity whose boundaries are not well defined and are in need of further study. Euphorbia graminea is often weedy and has recently become established in warmer areas of the southern United States, where it will likely become more common in the future. In recent years, a cultivar of E. graminea has found considerable horticultural success and is marketed under the trade name "Diamond Frost." (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 246. | FNA vol. 12, p. 275. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | E. dilatata, Chamaesyce lata, E. rinconis | |
Name authority | Jacquin: Select. Stirp. Amer. Hist., 151. (1763) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 188. (1859) |
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