Euphorbia oblongata |
Euphorbia radians |
|
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Balkan spurge, egg-leaf spurge, oblong spurge |
sun spurge |
|
Habit | Herbs, perennial, with woody taproot. | Herbs, perennial, with moniliform tuberous rootstock. |
Stems | erect, unbranched or densely branching, 80 cm, often densely villous (especially young stems and pleiochasial branches). |
erect, 5–20(–30) cm, usually glabrous, occasionally puberulent; branches ± straight. |
Leaves | petiole absent; blade oblong to narrowly obovate or lanceolate, 15–70 × 6–25 mm, base rounded or truncate, margins finely serrulate, apex obtuse, mucronulate, surfaces glabrous; venation inconspicuously pinnate, midvein prominent. |
alternate; petiole 0–2 mm, glabrous or strigose; blade linear-lanceolate to ovate or broadly elliptic, 25–50 × 3–20 mm, unlobed, base rounded (tapered to petiole), margins with few glandular teeth, strigillose, flat to revolute, apex acute, abaxial surface coarsely strigose, adaxial surface strigose-hirsute; venation pinnate, midvein prominent. |
Involucre | cupulate to slightly turbinate, 1.5–2.5 × 1.3–1.5 mm, glabrous; glands 2–3, elliptic, 0.6–0.8 × 0.8–1.2 mm; horns absent. |
broadly globose-cupulate, 1.7–2.1 × 2.2–2.5 mm, glabrous or puberulent; involucral lobes divided into triangular segments; glands 1–4(–5), white, sessile and broadly attached, 1.1 × 1.4 mm, opening oblong, glabrous; appendages absent. |
Staminate flowers | 15–40. |
20–25. |
Pistillate flowers | ovary glabrous; styles 1.5–2 mm, 2-fid. |
ovary glabrous or puberulent, styles 3–4 mm, 2-fid 1/2 to nearly entire length. |
Capsules | globose, 3–4.5 × 3–4.5 mm, slightly 3-lobed; cocci rounded, verrucose-tuberculate, glabrous; columella 2.5–3.3 mm. |
depressed-globose, 3.8–5 × 4–5 mm, 3-lobed, glabrous or puberulent; columella 3.6–4.5 mm. |
Seeds | brown, ovoid, 2.4–2.6 × 1.3–2 mm, smooth, caruncle reniform, 0.2–0.3 × 0.8–0.9 mm. |
white, mottled brown to gray, ellipsoid, rounded in cross section, 4–4.6 × 2.4–3.2 mm, smoothly and broadly pitted or grooved; caruncle 0.1 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 2–3 times 2–4-branched; pleiochasial bracts ovate, similar in size to distal leaves; dichasial bracts distinct, ovate to suborbiculate, base truncate or rounded, margins entire or finely denticulate, apex obtuse, sometimes mucronulate; axillary cymose branches 0–4. |
arrangement: terminal pleiochasial branches usually 3, occasionally reduced to congested cyme, 1–2-branched (often highly condensed); pleiochasial bracts 6–8(–10), as tight involucrate whorl, wholly white to pale pink or red, usually narrower than distal leaves; dichasial bracts linear and highly reduced. |
Cyathia | peduncle 1–5 mm. |
peduncle 2–5.5 mm. |
Euphorbia oblongata |
Euphorbia radians |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Waste areas, disturbed sites, roadsides, fields, pastures. | Pinyon-juniper woodlands, oak savannas, desert grasslands and scrub. |
Elevation | 30–900 m. (100–3000 ft.) | 700–2500 m. (2300–8200 ft.) |
Distribution |
CA; OR; WA; s Europe [Introduced in North America]
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AZ; TX; Mexico
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Discussion | Euphorbia oblongata is listed as a noxious weed by the states of California, Oregon, and Washington. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia radians is widely distributed but scattered from the Sonoran and Chihuahuan deserts south to Oaxaca in Mexico. The species is distinct among species in sect. Poinsettia in the flora area in its precocious habit, often flowering before the leaves emerge. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 324. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | Tithymalus oblongatus | Poinsettia radians |
Name authority | Grisebach: Spic. Fl. Rumel. 1: 136. (1843) | Bentham: Pl. Hartw., 8. (1839) |
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