Euphorbia dentata |
Euphorbia corollata |
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green poinsettia, tooth poinsettia, tooth spurge |
eastern flowering spurge, flowering spurge, floweringspurge euphorbia |
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Habit | Herbs, annual, with taproot. | Herbs, perennial, with deep, spreading rootstock. |
Stems | erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
erect or ascending, usually unbranched, occasionally few branched, solitary or few, previous year's dead stems not persistent, 20–100 cm, glabrous or slightly pilose to villous. |
Leaves | usually opposite, occasionally alternate at distal nodes; petiole 5–20 mm, pilose; blade 30–70 × 4–35 mm, narrowly lanceolate to suborbiculate, usually broadest below middle, base usually acute to subobtuse, rarely subtruncate, margins coarsely crenate-dentate or doubly crenate, strigillose, flat to slightly revolute, apex broadly acute, abaxial surface long pilose with weak, filiform hairs, adaxial surface sparsely pilose to glabrate; venation pinnate, midvein prominent. |
alternate, ascending; stipules 0.1–0.2 mm; petiole minute or absent; blade oblanceolate, obovate, or elliptic, 25–55 × 5–12 mm, base cuneate to rounded, margins entire, occasionally slightly revolute, apex rounded to subacute, abaxial surface glabrous or pilose to villous, adaxial surface usually glabrous, rarely villous; venation occasionally obscure on small leaves, midvein conspicuous. |
Involucre | campanulate, 3.8 × 1.8 mm, glabrous; involucral lobes divided into several linear, smooth lobes; glands (1–)2, green, sessile and broadly attached, 0.7–0.9 × 0.9–1.2 mm, opening oblong, glabrous; appendages absent. |
campanulate, 1.2–1.5 × 1.2–1.5(–2) mm, glabrous or moderately puberulent (especially near glands); glands 5, green, reniform, 0.5 × 0.8–1 mm; appendages white, flabellate, 2.5–3.5(–4.5) × 2.5–3.2 mm, entire. |
Staminate flowers | 8–10. |
20–25. |
Pistillate flowers | ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 0.8–1.4 mm, 2-fid at apex to 1/2 length. |
Capsules | depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 mm. |
globose, 2.3–3 × 3.5–4.2 mm, glabrous; columella 2–2.5 mm. |
Seeds | pale gray to black, ovoid, rounded in cross section, 2.1–2.7 × 1.7–2.1 mm, evenly minute-tuberculate; caruncle 0.4–0.6 mm. |
white or light gray, ovoid, 2.5–2.8 × 2.2 mm, with shallow and coarse depressions; caruncle absent. |
Cyathial | arrangement: terminal pleiochasial branches usually 3, occasionally reduced to congested cyme, 1–2-branched; pleiochasial bracts 2–4, often whorled, wholly green or paler green, white, or mauve at base, similar in shape and size to distal leaves or slightly narrower; dichasial bracts similar in shape to distal leaves but smaller (often highly reduced). |
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Cyathia | peduncle 0.7–1 mm. |
in terminal pleiochasia, dichasial bracts occasionally whorled or rarely alternate; peduncle (1.5–)5–11(–13) mm (proximal to 70 mm), glabrous. |
2n | = 28. |
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Euphorbia dentata |
Euphorbia corollata |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting early summer–fall. |
Habitat | Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. | Prairies, open fields, upland woods, glades, barrens, borders of swamps, roadsides, disturbed sites. |
Elevation | 0–1000 m. (0–3300 ft.) | 0–1300 m. (0–4300 ft.) |
Distribution |
AL; AR; GA; IA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; OH; OK; PA; SC; TN; TX; VA; WV; ON; Mexico (Chihuahua, Coahuila, Nuevo León, Tamaulipas)
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AL; AR; CT; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; ON
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Discussion | Euphorbia dentata is native from northern Mexico and the south central United States north and east through the Ohio River Valley. Scattered occurrences in the southeastern United States likely represent adventive populations. Reports of E. dentata as a noxious weed (from the United States and the Old World) should most likely be attributed to introductions of E. davidii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia corollata is morphologically variable and widely distributed across a large part of eastern North America. The species appears to be expanding its range, as adventive populations have been reported from disturbed habitats at the northern edge of its range in Maine, Massachusetts, Michigan, Minnesota, New Hampshire, South Dakota, and Vermont. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 244. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Poinsettia dentata | E. corollata var. molle, E. corollata var. viridiflora, E. marilandica, E. olivacea, Tithymalopsis corollata, T. olivacea |
Name authority | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | Linnaeus: Sp. Pl. 1: 459. (1753) |
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