Euphorbia marginata |
Euphorbia lathyris |
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euphorbe marginée, mountain snow spurge, smoke-on-the-prairie, snow-on-the-mountain, variegated spurge, whitemargined spurge |
caper spurge, euphorbe épurge, gopher plant, gopher spurge, mole plant |
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Habit | Herbs, annual, with taproot. | Herbs, annual or biennial, with taproot. |
Stems | erect, unbranched or branched, 30–85(–150) cm, pilose or glabrous. |
erect, unbranched or branched, 200 cm, glabrous, glaucous. |
Leaves | alternate; stipules 0.1–0.3 mm; petiole 0.2–3 mm, glabrous or minutely pilose; blade broadly ovate to elliptic, 32–62(–82) × 18–28(–52) mm, base rounded to cuneate, margins entire, often white on distal leaves, apex acute, rarely mucronate, surfaces glabrous; venation obscure, only midvein conspicuous. |
opposite, decussate; petiole absent; blade linear to oblong-lanceolate, 30–120 × 3–25 mm, base acute, rounded, cordate or clasping, margins entire, apex acute or subobtuse, sometimes mucronate, surfaces glabrous, abaxial ± glaucous; venation pinnate, midvein prominent. |
Involucre | campanulate, 2.2–3.5 × 1.3–2.3 mm, margin between glands deeply divided into fringe of fimbriate lobes, pilose; glands 4–5, green to greenish yellow, reniform to subcircular, 0.7–1.1 × 1–1.6 mm; appendages white, orbiculate, 1.5–2.7 × 1.9–2.9(–3.6) mm, entire. |
campanulate, 1.2–2.3 × 1.4–2.5 mm, glabrous; glands 4, elliptic, 0.3–0.6 × 1–1.3 mm; horns divergent, thick, tips rounded, dilated, 0.5–1.4 mm. |
Staminate flowers | 30–70. |
25–30. |
Pistillate flowers | ovary pilose; styles 1–2.5 mm, 2-fid 1/2–2/3 length. |
ovary glabrous; styles 0.7–2.2 mm, 2-fid. |
Capsules | oblate, 3–5 × 3.5–7.5 mm, moderately to densely pilose; columella 3–4.1 mm. |
depressed-globose, 9–12 × 12–16 mm, deeply 3-lobed, tardily dehiscent and appearing indehiscent, mesocarp spongy; cocci rounded, smooth, glabrous; columella 4–5.2 mm. |
Seeds | orange-tan to gray, ovoid, 3.7–3.9 × 3–3.3 mm, rugose, with 2 transverse ridges (one dark orange to brown, other inconspicuous); caruncle absent. |
brownish or blackish, oblong, 4.5–6 × 3–4.2 mm, rugose, irregularly reticulate; caruncle substipitate, hat-shaped, 1.6–2 × 1.2–1.5 mm. |
Cyathia | in terminal pleiochasia, dichasial bracts narrowly elliptic to oblanceolate with conspicuous white margins; peduncle 1.8–2.7(–22) mm, densely pilose. |
peduncle 0–0.5 mm. |
Cyathial | arrangement: terminal pleiochasial branches 2–4, each 1–2 times 2-branched; pleiochasial bracts cordate-lanceolate, shorter and wider than distal leaves; dichasial bracts distinct, ovate-oblong to lanceolate, base subcordate, margins entire, apex acute; axillary cymose branches 0–10. |
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2n | = 56. |
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Euphorbia marginata |
Euphorbia lathyris |
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Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting winter–fall. |
Habitat | Disturbed areas and grasslands. | Roadsides, cultivated fields, stream banks, waste places. |
Elevation | 0–1700 m. (0–5600 ft.) | 0–1800 m. (0–5900 ft.) |
Distribution |
AR; CA; CO; CT; IA; IL; IN; KS; LA; MA; MD; MI; MN; MO; MT; NC; NE; NH; NM; NY; OH; OK; PA; RI; SC; SD; TN; TX; UT; VA; WI; WV; WY; MB; ON; QC; SK; c Mexico; s Mexico
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AZ; CA; CT; ID; IL; MA; MD; MT; NC; OH; OR; PA; SC; TN; TX; VA; WA; WV; BC; ON; QC; Europe; Asia; Africa [Introduced in North America; introduced also in Mexico, South America, Australia]
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Discussion | Euphorbia marginata is native to the central United States. The type specimen was collected by Meriwether Lewis along the Yellowstone River in southern Montana in 1806, and it has been reported to be native as far south as Arizona, New Mexico, and Texas, and as far east as southern Minnesota, western Iowa, and Missouri (G. Yatskievych 1999–2013, vol. 2). It is presumably naturalized outside of this area. Euphorbia marginata is widely cultivated as an ornamental for its showy, white-margined distal leaves, and it can escape locally. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia lathyris is most likely native to the central and eastern Mediterranean region, but it is widely cultivated and often locally escaped in temperate regions worldwide, as in the flora area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 248. | FNA vol. 12, p. 304. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | E. bonplandii, Lepadena marginata | Galarhoeus lathyris, Tithymalus lathyris |
Name authority | Pursh: Fl. Amer. Sept. 2: 607. (1813) | Linnaeus: Sp. Pl. 1: 457. (1753) — (as lathyrus) |
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