Euphorbia agraria |
Euphorbia porteriana |
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urban spurge |
Porter's sandmat |
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Habit | Herbs, perennial, with slender, spreading rootstock. | Herbs, usually annual, sometimes perennial, with slender to occasionally thickened taproot, 5 mm diam.. |
Stems | erect or ascending, unbranched or branched, 30–90 cm, glabrous. |
erect to ascending, sometimes slightly woody at base, not mat-forming, 15–60 cm, usually glabrous, young branches rarely very sparsely short pubescent. |
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 usually distinct, occasionally connate basally, triangular, entire or 2–4 parted, apically ciliate, 0.3–0.4 mm, usually glabrous, rarely very sparsely short pubescent; petiole 0.5–1.5 mm, usually glabrous, rarely very sparsely short pubescent; blade ovate, oval, elliptic, oblong-elliptic, or linear-elliptic, 4–12 × 1–7 mm, base asymmetric, rounded or subcordate, margins usually entire, rarely sparsely serrate, apex obtuse to acute, sometimes mucronate, surfaces abaxially often purple or red, adaxially green, usually glabrous, rarely very sparsely short pubescent; 3-veined from base, only midvein conspicuous. |
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. |
turbinate to campanulate, 0.7–1 × 0.8–1 mm, usually glabrous, rarely very sparsely short pubescent; glands 4, brown, slightly concave, elliptic-oblong, 0.1–0.2 × 0.3–0.6 mm; appendages white or pink to dark red, usually oblong or flabellate, occasionally rudimentary and forming narrow rim at edge of gland, (0–)0.1–0.2 × 0.4–1 mm, distal margin entire or crenulate. |
Staminate flowers | 15–20. |
8–14. |
Pistillate flowers | ovary glabrous; styles 1.2–2 mm, 2-fid. |
ovary glabrous, subtended by triangular calyxlike structure; styles 0.4–0.6 mm, 2-fid 1/2 length. |
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. |
broadly ovoid, 1–1.5 × 1.7–2.1 mm, glabrous; columella 1–1.4 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. |
reddish brown, ovoid, 4-angled in cross section, 0.7–1 × 0.6–0.7 mm, smooth or obscurely wrinkled. |
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; peduncle 0.5–1.1 mm. |
Euphorbia agraria |
Euphorbia porteriana |
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Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round. |
Habitat | Grasslands, roadside banks, pastures. | Pine rocklands, coastal scrub, open hammocks. |
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 |
Discussion | Euphorbia porteriana is found in Miami-Dade County and on Big Pine Key, Monroe County. This species is closely related to E. blodgettii, E. garberi, and E. serpens. The capsules of E. porteriana are almost always completely glabrous, but the authors have seen three specimens with just a few scattered hairs on the keels. A. Herndon (1993) synonymized E. porteriana var. keyensis under E. garberi because of its uniformly hairy capsules, and that treatment is followed here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 285. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalus agrarius | Chamaesyce porteriana, C. porteriana var. scoparia, C. scoparia |
Name authority | M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) | (Small) Oudejans: Phytologia 67: 48. (1989) |
Web links |