Euphorbia commutata |
Euphorbia radians |
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tinted euphorbia, tinted woodland spurge |
sun spurge |
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Habit | Herbs, usually biennial, occasionally annual, with taproot. | Herbs, perennial, with moniliform tuberous rootstock. |
Stems | erect or ascending, decumbent and often branched near base, 10–40 cm, glabrous. |
erect, 5–20(–30) cm, usually glabrous, occasionally puberulent; branches ± straight. |
Leaves | petiole usually 5–10 mm, 0–1 mm distally; blade usually oblanceolate to obovate, rarely ovate, 5–30 × 3–10 mm, base broadly attenuate, margins entire, apex usually obtuse to rounded, occasionally slightly retuse, surfaces glabrous; venation 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 | campanulate, 1.7–2.5 × 1.5–2.5 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 0.8–1.5 mm; horns divergent, 0.5–1.1 mm. |
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 | 9–15. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.9–1.3 mm, 2-fid. |
ovary glabrous or puberulent, styles 3–4 mm, 2-fid 1/2 to nearly entire length. |
Capsules | ovoid-globose, 2.5–3.2 × 3 mm, slightly lobed; cocci rounded to ± flattened, smooth, glabrous; columella 1.5–2 mm. |
depressed-globose, 3.8–5 × 4–5 mm, 3-lobed, glabrous or puberulent; columella 3.6–4.5 mm. |
Seeds | white to gray, broadly oblong-elliptic to ovoid or nearly globose, 1.5–2 × 1.3–1.6 mm, strongly small-pitted; caruncle irregularly winglike, conic, 0.6–1 × 0.7–0.9 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 (2–)3(–4), 1–3+ times 2-branched; pleiochasial bracts similar in shape and size to distal leaves; dichasial bracts distinct to basally subconnate, not imbricate, widely ovate, rhombic, or reniform, base cordate, rarely slightly perfoliate, margins entire, apex obtuse to rounded, mucronulate; axillary cymose branches 0–5. |
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 0.5–1 mm. |
peduncle 2–5.5 mm. |
Euphorbia commutata |
Euphorbia radians |
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Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–summer. |
Habitat | Bottomland and upland forests, bluffs and ledges, stream banks, glades, rarely fen margins. | Pinyon-juniper woodlands, oak savannas, desert grasslands and scrub. |
Elevation | 50–1000 m. (200–3300 ft.) | 700–2500 m. (2300–8200 ft.) |
Distribution |
AL; AR; FL; GA; IA; IL; IN; KY; LA; MD; MI; MO; MS; NC; OH; OK; PA; SC; TN; VA; WI; WV; ON
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AZ; TX; Mexico
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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.) |
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Source | FNA vol. 12, p. 300. | FNA vol. 12, p. 324. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | Galarhoeus austrinus, G. commutatus, Tithymalus commutatus | Poinsettia radians |
Name authority | Engelmann: in A. Gray, Manual ed. 2, 389. (1856) | Bentham: Pl. Hartw., 8. (1839) |
Web links |