Euphorbia dentata |
Euphorbia missurica |
|
---|---|---|
green poinsettia, tooth poinsettia, tooth spurge |
Missouri spurge, prairie sandmat, prairie spurge |
|
Habit | Herbs, annual, with taproot. | Herbs, annual, with taproot. |
Stems | erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
erect or ascending, 10–60(–100) cm, glabrous, sometimes ± glaucous. |
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 usually distinct, occasionally connate basally on one or both sides of stem, linear to triangular-subulate, usually deeply and irregularly fringed or lobed, rarely entire, 0.7–1.5 mm, glabrous; petiole 1–3 mm, glabrous; blade linear to narrowly oblong or narrowly lanceolate-oblong, (4–)8–30 × 3–7 mm, base symmetric or subsymmetric (usually narrower leaves), or slightly asymmetric and angled or short-tapered (wider leaves), margins entire, occasionally ± revolute, apex rounded to truncate, occasionally emarginate or mucronulate, abaxial surface pale green, adaxial surface light to bright green, both surfaces glabrous; venation obscure. |
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. |
broadly campanulate, 1.2–1.8 × 1.7–1.9 mm, glabrous; glands 4, yellowish green, broadly oblong to nearly circular, cupped or folded, 0.3–0.6 × 0.3–0.7 mm; appendages white or ± pinkish tinged, ovate to oblong-ovate, 0.4–2.5 × 1.1–1.7 mm, distal margin entire or slightly crenate or emarginate at tip. |
Staminate flowers | 8–10. |
24–60. |
Pistillate flowers | ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 0.5–1.4 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. |
broadly ovoid-globose, 1.9–2.5 × 2–2.5(–3) mm, 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. |
mottled whitish to brown, ovoid to broadly ovoid-triangular, bluntly 3-angled in cross section, 1.5–2 × 1.1–1.4 mm, smooth or slightly wrinkled. |
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 or in small, cymose clusters these occasionally subtended by reduced, bractlike leaves at distal nodes or on congested, axillary branches; peduncle 1–5(–11) mm. |
2n | = 28. |
|
Euphorbia dentata |
Euphorbia missurica |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting late spring–late summer. |
Habitat | Bottomland forests, stream and river banks, bluffs, prairies, glades, fallow fields, roadsides, railroad cinders, open disturbed areas. | Glades, ledges, bluff tops (usually calcareous), dry upland forest margins, sandy or disturbed areas. |
Elevation | 0–1000 m. (0–3300 ft.) | 50–1500 m. (200–4900 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)
|
AR; CO; IA; KS; MO; MT; ND; NE; NM; OK; SD; TX; WY
|
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 missurica is similar to the western E. parryi but has a more upright growth habit and more conspicuous involucral gland appendages. Native occurrences have been documented from Minnesota (last collected in Ottertail County in 1936), but it appears to have been extirpated from that state due to habitat loss to agriculture. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 278. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Poinsettia dentata | Chamaesyce missurica, E. missurica var. intermedia, E. petaloidea var. intermedia |
Name authority | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | Rafinesque: Atlantic J. 1: 146. (1832) |
Web links |
|