Euphorbia dentata

Michaux

Fl. Bor.-Amer. 2: 211. 1803.

Common names: Toothed spurge
Synonyms: Poinsettia dentata (Michaux) Klotzsch & Garcke
Treatment appears in FNA Volume 12. Treatment on page 321. Mentioned on page 318, 320.

Herbs, annual, with taproot. Stems erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. 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. 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. 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. Staminate flowers 8–10. Pistillate flowers: ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. Capsules depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 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. 2n = 28.


Phenology: Flowering and fruiting spring–fall.
Habitat: Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas.
Elevation: 0–1000 m.

Distribution

V12 784-distribution-map.jpg

Ont., Ala., Ark., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Mich., Miss., Mo., Nebr., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va., Mexico (Chihuahua), Mexico (Coahuila), Mexico (Nuevo León), Mexico (Tamaulipas)

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.

Selected References

None.

Lower Taxa

None.

No values specified."narrower" is not a number."connate" is not a number. "distinct" is not a number."entire" is not a number.

... more about "Euphorbia dentata"
sparsely pilose +  and glabrate +
Jess A. Peirson +, Paul E. Berry +  and Victor W. Steinmann +
Michaux +
connate +
usually acute +  and subobtuse +
Poinsettia +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
narrowly lanceolate;suborbiculate +
dichasial +  and pleiochasial +
mauve +, white +, paler green +  and green +
distinct +
2 +  and 4 +
cymose +, few-branched +, unbranched +  and pleiochasial +
arranged +  and opposite +
additional +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
3-lobed +  and depressed-globose +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
Toothed spurge +
Ont. +, Ala. +, Ark. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Md. +, Mich. +, Miss. +, Mo. +, Nebr. +, N.C. +, Ohio +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +, Va. +, W.Va. +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Nuevo León) +  and Mexico (Tamaulipas) +
0–1000 m. +
pistillate +  and staminate +
0.7mm;0.9mm +
subtending +
0.9mm +  and 1.2mm +
Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. +
filiform +
axillary +  and terminal +
3.8 cm38 mm <br />0.038 m <br /> (?) +
campanulate +
1.8 cm18 mm <br />0.018 m <br /> (?) +
alternate +  and opposite +
caducous +, deciduous +  and persistent +
bractlike +
involucral +
divided +
palmate +  and pinnate +
serrulate +, crenate-dentate +  and entire +
strigillose +
flat +  and slightly revolute +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
connate;distinct +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Flowering and fruiting spring–fall. +
Fl. Bor.-Amer. +
pale gray;black +
0.21 cm2.1 mm <br />0.0021 m <br /> (0.27 cm2.7 mm <br />0.0027 m <br />) +
minute-tuberculate +
rounded +  and ovoid +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
free +, connate +  and distinct +
ascending +  and erect +
strigillose +  and pilose +
15 cm150 mm <br />0.15 m <br /> (60 cm600 mm <br />0.6 m <br />) +
deciduous +  and persistent +
distinct +
1.2 cm12 mm <br />0.012 m <br /> (?) +
hairy +  and glabrous +
Poinsettia dentata +
Euphorbia dentata +
Euphorbia sect. Poinsettia +
species +
1-2-branched +  and pleiochasial +