Euphorbia radians |
Euphorbia dendroides |
|
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sun spurge |
tree spurge |
|
Habit | Herbs, perennial, with moniliform tuberous rootstock. | Shrubs, dendroid, with large rootstock. |
Stems | erect, 5–20(–30) cm, usually glabrous, occasionally puberulent; branches ± straight. |
erect, stout, densely branched, to 200 cm, glabrous, bark usually reddish and glossy toward tip of branches. |
Leaves | 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. |
petiole absent; blade linear-lanceolate to oblong-lanceolate, 20–65 × 3–8 mm, base attenuate, margins entire, apex obtuse to acute, sometimes mucronulate, surfaces glabrous; venation pinnate, midvein prominent, base attenuate. |
Involucre | 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. |
broadly turbinate to hemispheric, 3–4 × 3.5–3.8 mm, glabrous; glands 4, suborbiculate to subtrapezoidal, 1–1.5 × 1.2–1.8 mm, sometimes irregularly lobed; horns absent. |
Staminate flowers | 20–25. |
20–25. |
Pistillate flowers | ovary glabrous or puberulent, styles 3–4 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 2.4–3 mm, 2-fid. |
Capsules | depressed-globose, 3.8–5 × 4–5 mm, 3-lobed, glabrous or puberulent; columella 3.6–4.5 mm. |
subglobose, 4–5.5 × 4–6.5 mm, deeply lobed; cocci laterally compressed, smooth, glabrous; columella 3–4 mm. |
Seeds | 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. |
grayish or blackish, ovoid and strongly laterally compressed, 3–3.5 × 1.5–2 mm, smooth; caruncle semirounded and laterally compressed, 1.2–1.4 × 0.8–1.8 mm. |
Cyathial | 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. |
arrangement: terminal pleiochasial branches 4–8, unbranched or 1–2-times 2-branched; pleiochasial bracts similar in shape to but usually shorter and wider than distal leaves; dichasial bracts distinct, yellowish, broadly ovate, orbiculate, rhombic, or reniform, base obtuse, margins entire, apex obtuse, sometimes mucronulate; axillary pleiochasial absent. |
Cyathia | peduncle 2–5.5 mm. |
peduncle absent. |
Euphorbia radians |
Euphorbia dendroides |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting fall–spring. |
Habitat | Pinyon-juniper woodlands, oak savannas, desert grasslands and scrub. | Coastal plains and basins, hillsides. |
Elevation | 700–2500 m. (2300–8200 ft.) | 0–500 m. (0–1600 ft.) |
Distribution |
AZ; TX; Mexico
|
CA; Europe; n Africa [Introduced in North America] |
Discussion | 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.) |
Euphorbia dendroides is native to the Mediterranean region. In the flora area, the species is known from Los Angeles, Santa Barbara, and Ventura counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 324. | FNA vol. 12, p. 302. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Poinsettia radians | Tithymalus dendroides |
Name authority | Bentham: Pl. Hartw., 8. (1839) | Linnaeus: Sp. Pl. 1: 462. (1753) |
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