Euphorbia dentata |
Euphorbia parishii |
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green poinsettia, tooth poinsettia, tooth spurge |
Parish's sandmat |
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Habit | Herbs, annual, with taproot. | Herbs or subshrubs, perennial, with thickened and often woody rootstock. |
Stems | erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
prostrate, sometimes forming dense mounds, 10–50 cm, glabrous. |
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. |
opposite; stipules distinct, subulate-filiform, 0.3–0.9 mm, pilose; petiole 0.3–1.2 mm, glabrous; blade usually ovate, rarely oblong, 2–7 × 1–5 mm, base usually asymmetric, rounded to hemicordate, margins entire, apex usually obtuse, rarely acute, surfaces glabrous; only 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. |
obconic to campanulate, 1–1.4 × 0.9–1.3 mm, glabrous except for pilose lobes; glands 4, pink to maroon, circular, 0.3–0.4 × 0.3–0.4 mm; appendages absent. |
Staminate flowers | 8–10. |
40–50. |
Pistillate flowers | ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 0.3–0.6 mm, 2-fid 1/2 length. |
Capsules | depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 mm. |
ovoid to oblate-ovoid, 1.6–1.7 × 1.6–1.9 mm, glabrous; columella 1.2–1.5 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. |
whitish to light brown, ovoid, 4-angled in cross section, 1.2–1.4 × 0.6–0.8 mm, rugose or with indistinct, irregular, low transverse ridges. |
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. |
solitary at distal nodes; peduncle 0.1–0.6(–2.2) mm. |
2n | = 28. |
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Euphorbia dentata |
Euphorbia parishii |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting fall–summer. |
Habitat | Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. | Desert scrub, often with creosote bush, disturbed roadsides, rocky soils. |
Elevation | 0–1000 m. (0–3300 ft.) | -90–600 m. (-300–2000 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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CA; NV |
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 parishii is common in the Death Valley region of southern California, where it is often encountered well below sea level. The species is frequently confused with E. micromera and E. polycarpa but differs from the former in being a more robust plant with larger cyathia and from the latter in lacking involucral gland appendages. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 280. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Poinsettia dentata | Chamaesyce parishii, E. polycarpa var. parishii |
Name authority | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | Greene: Bull. Calif. Acad. Sci. 2: 56. (1886) |
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