Euphorbia dentata |
Euphorbia telephioides |
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green poinsettia, tooth poinsettia, tooth spurge |
telephus spurge |
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Habit | Herbs, annual, with taproot. | Herbs, perennial, with thickened rootstock. |
Stems | erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
erect or ascending, 20–30 cm. |
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. |
petiole usually absent or indistinct, occasionally to 5.5 mm, blade elliptic or obovate, 31–60 × 7–32 mm, thick and fleshy, base attenuate or cuneate, apex acute, obtuse, or mucronate; venation pinnate with 8–13 lateral veins, these sometimes obscure and only midvein evident. |
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, 1.3–2.3 × 1.6–2.5 mm, lobes ovate to oblong, 0.5–0.7 mm, ciliate; glands purple-red, oblong to trapezoidal, 0.5–0.7 × 0.8–1.2 mm, distal margins entire or crenulate. |
Staminate flowers | 8–10. |
25–30. |
Pistillate flowers | ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
gynophore exserted 1.9–3.2 mm, calyxlike lobes triangular, 0.2–0.7 mm; styles connate 1/4 length, 1.3–1.5 mm. |
Capsules | depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 mm. |
ovoid-oblate, 5.2–5.6 × 6.6–8.3 mm, 3-lobed; columella 3.9–4.1 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. |
blackish to dark brown, ovoid to globose-ovoid, circular in cross section, 3.2–3.5 × 2.6–3.1 mm, smooth, base rounded to flattened, apex rounded, occasionally with low point. |
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). |
arrangement: terminal pleiochasial branches (2–)3, 5–13 cm, 3–7 times 2-branched; pleiochasial bracts ovate to oblong, 17–31 × 8–15 mm, margins entire, apex acute or obtuse; dichasial bracts ovate, 5–19 × 3–9 mm, margins entire, apex acute or obtuse; axillary cymose branches 1–5. |
Cyathia | peduncle 0.7–1 mm. |
peduncle 3–9.2 mm (often exceeding subcyathial leaves). |
2n | = 28. |
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Euphorbia dentata |
Euphorbia telephioides |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. | Scrubby pine flatwoods, grasslands, disturbed areas, often in sandy soils. |
Elevation | 0–1000 m. (0–3300 ft.) | 0–20 m. (0–100 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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FL |
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 telephioides, federally listed as threatened, is known only from Bay, Franklin, and Gulf counties in the Apalachicola region of the east-central Florida panhandle. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 316. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | Poinsettia dentata | Galarhoeus telephioides |
Name authority | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | Chapman: Fl. South. U.S., 402. (1860) |
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