Euphorbia agraria |
Euphorbia pergamena |
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urban spurge |
rocklands spurge, Southern Florida sandmat |
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Habit | Herbs, perennial, with slender, spreading rootstock. | Herbs, perennial, with moderately to strongly thickened rootstock. |
Stems | erect or ascending, unbranched or branched, 30–90 cm, glabrous. |
prostrate to ascending, occasionally mat-forming, terete to slightly flattened, 5–18 cm, glabrous on lower surface, strigillose to sericeous on upper surface. |
Leaves | petiole absent; blade oblong-elliptic, 20–65 × 9–20 mm, base truncate to auriculate, margins entire, apex obtuse to rounded, surfaces glabrous; venation conspicuously pinnate, midvein prominent. |
opposite; stipules distinct, subulate, better developed on lower side of stem, 0.4–1.3 mm, glabrous or pilose; petiole 0.3–0.5 mm, puberulent, sericeous, or strigillose; blade oblong to ovate, 4–7 × 2–4 mm, base asymmetric, hemicordate, larger side sometimes amplexicaulous, margins entire or serrulate, apex obtuse, surfaces puberulent, sericeous, or strigillose; 3-veined from base, lateral veins inconspicuous. |
Involucre | campanulate, 2.2–3 × 1.8–2 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 1–2 mm; horns slightly divergent to convergent, 0.1–0.2 mm. |
campanulate, 1–1.3 × 1–1.1 mm, canescent; glands 4, pinkish, oblong or reniform, 0.2 × 0.4–0.6 mm; appendages white to pink, lunate, unequal, those of proximal glands oblique, 0.6–1 × 1.4–1.6 mm, those of distal glands symmetric, 0.3 × 0.8–0.9 mm, irregularly undulate to incised. |
Staminate flowers | 15–20. |
15. |
Pistillate flowers | ovary glabrous; styles 1.2–2 mm, 2-fid. |
ovary puberulent, sericeous or strigillose; styles 0.5–1 mm, 2-fid at apex. |
Capsules | globose, 2–2.8 × 2.2–2.7 mm, 3-lobed; cocci rounded, smooth except finely granulate toward abaxial line, glabrous; columella 2.1–2.7 mm. |
oblate, well exserted from involucre at maturity, 1–1.3 × 1.3–1.8 mm, puberulent, sericeous or strigillose; columella 1 mm. |
Seeds | gray or whitish, ovoid-oblong, 2–2.1 × 1.2–1.3 mm, smooth; caruncle ± rounded and flattened, 0.8 × 0.6 mm. |
whitish to gray, ovoid, 4-angled in cross section, 0.7–0.8 × 0.5–0.6 mm, with 3–4 transverse sulci alternating with low transverse ridges. |
Cyathial | arrangement: terminal pleiochasial branches 8–15, 1–2 times 2-branched; pleiochasial bracts similar in shape but shorter and narrower than distal leaves; dichasial bracts distinct, rhombic to reniform, base obtuse, margins entire, apex obtuse, mucronate; axillary cymose branches 12–23. |
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Cyathia | peduncle 0–2 mm. |
solitary at distal nodes or at nodes of short, congested, axillary shoots; peduncle to 0.5 mm. |
Euphorbia agraria |
Euphorbia pergamena |
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Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round. |
Habitat | Grasslands, roadside banks, pastures. | Crevices of limestone outcrops in pinelands and pine-palm woods. |
Elevation | 200–1600 m. (700–5200 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
KS; MT; NE; NY; PA; WA; WY; AB; SK; Europe [Introduced in North America]
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FL; West Indies (Cuba, Hispaniola) |
Discussion | Euphorbia pergamena is a Florida-listed threatened species known within the flora area from only Miami-Dade and Monroe counties in extreme southern Florida. The species is often included as a subspecies of E. adenoptera (for example, D. G. Burch 1965), but here A. Herndon (1993b) is followed and it is treated as a distinct species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 282. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalus agrarius | Chamaesyce adenoptera subsp. pergamena, C. pergamena, E. adenoptera subsp. pergamena |
Name authority | M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) | Small: Bull. Torrey Bot. Club 25: 615. (1898) |
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