Euphorbia dentata |
Euphorbia pergamena |
|
---|---|---|
green poinsettia, tooth poinsettia, tooth spurge |
rocklands spurge, Southern Florida sandmat |
|
Habit | Herbs, annual, with taproot. | Herbs, perennial, with moderately to strongly thickened rootstock. |
Stems | erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
prostrate to ascending, occasionally mat-forming, terete to slightly flattened, 5–18 cm, glabrous on lower surface, strigillose to sericeous on upper surface. |
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, better developed on lower side of stem, 0.4–1.3 mm, glabrous or pilose; petiole 0.3–0.5 mm, puberulent, sericeous, or strigillose; blade oblong to ovate, 4–7 × 2–4 mm, base asymmetric, hemicordate, larger side sometimes amplexicaulous, margins entire or serrulate, apex obtuse, surfaces puberulent, sericeous, or strigillose; 3-veined from base, lateral veins inconspicuous. |
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, 1–1.3 × 1–1.1 mm, canescent; glands 4, pinkish, oblong or reniform, 0.2 × 0.4–0.6 mm; appendages white to pink, lunate, unequal, those of proximal glands oblique, 0.6–1 × 1.4–1.6 mm, those of distal glands symmetric, 0.3 × 0.8–0.9 mm, irregularly undulate to incised. |
Staminate flowers | 8–10. |
15. |
Pistillate flowers | ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
ovary puberulent, sericeous or strigillose; styles 0.5–1 mm, 2-fid at apex. |
Capsules | depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 mm. |
oblate, well exserted from involucre at maturity, 1–1.3 × 1.3–1.8 mm, puberulent, sericeous or strigillose; columella 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. |
whitish to gray, ovoid, 4-angled in cross section, 0.7–0.8 × 0.5–0.6 mm, with 3–4 transverse sulci alternating with 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). |
|
Cyathia | peduncle 0.7–1 mm. |
solitary at distal nodes or at nodes of short, congested, axillary shoots; peduncle to 0.5 mm. |
2n | = 28. |
|
Euphorbia dentata |
Euphorbia pergamena |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting year-round. |
Habitat | Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. | Crevices of limestone outcrops in pinelands and pine-palm woods. |
Elevation | 0–1000 m. (0–3300 ft.) | 0–10 m. (0–0 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)
|
FL; West Indies (Cuba, Hispaniola) |
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 pergamena is a Florida-listed threatened species known within the flora area from only Miami-Dade and Monroe counties in extreme southern Florida. The species is often included as a subspecies of E. adenoptera (for example, D. G. Burch 1965), but here A. Herndon (1993b) is followed and it is treated as a distinct species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 282. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Poinsettia dentata | Chamaesyce adenoptera subsp. pergamena, C. pergamena, E. adenoptera subsp. pergamena |
Name authority | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | Small: Bull. Torrey Bot. Club 25: 615. (1898) |
Web links |
|