Euphorbia ocellata |
Euphorbia dentata |
|||||
---|---|---|---|---|---|---|
Contura Creek sandmat, Contura Creek spurge, valley spurge |
green poinsettia, tooth poinsettia, tooth spurge |
|||||
Habit | Herbs, annual, with taproot. | Herbs, annual, with taproot. | ||||
Stems | prostrate, 10–35 cm, glabrous or pilose. |
erect or ascending, 15–60 cm, both pilose and inconspicuously strigillose; branches usually ± straight, occasionally proximal branches arcuate. |
||||
Leaves | opposite; stipules distinct, subulate, 0.5–1.6 mm, glabrous or pilose; petiole 0.3–2 mm, glabrous or pilose; blade ovate to deltate or falcate, 2.3–13 × 1.5–6 mm, base asymmetric, usually cordate, rarely rounded, margins occasionally reddish, entire, often revolute, apex acute to obtuse, occasionally mucronate, surfaces glabrous or pilose; midvein conspicuous, lateral veins frequently visible abaxially. |
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. |
||||
Involucre | campanulate, 1–2.5 × 1.3–2.4 mm, glabrous or pilose; glands 4, yellow becoming deep red, elliptic or oblong to orbiculate, 0.4–0.6 × 0.5–0.7 mm; appendages absent or whitish, orbiculate, 0.1–0.2 × 0.3–0.5 mm, distal margin entire. |
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 | 30–70. |
8–10. |
||||
Pistillate flowers | ovary glabrous or pilose; styles 0.4–0.5 mm, 2-fid at apex. |
ovary glabrous, styles 1.2 mm, 2-fid 1/2 to nearly entire length. |
||||
Capsules | subglobose to broadly ovoid, 1.4–2.7 × 1.9–3.1 mm, glabrous or pilose; columella 1.4–2 mm. |
depressed-globose, 2.5–2.8 × 3.5–4 mm, 3-lobed, glabrous; columella 1.8–2.1 mm. |
||||
Seeds | whitish gray to black, ovoid to oblong, terete to bluntly subangled in cross section, 1.1–1.7 × 0.8–1.3 mm, rugose or smooth. |
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. |
||||
Cyathia | solitary at distal nodes; peduncle 0.9–2.2 mm. |
peduncle 0.7–1 mm. |
||||
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). |
|||||
2n | = 28. |
|||||
Euphorbia ocellata |
Euphorbia dentata |
|||||
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. (0–3300 ft.) | |||||
Distribution |
AZ; CA; ID; NV; UT
|
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)
|
||||
Discussion | Subspecies 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
||||
Key |
|
|||||
Source | FNA vol. 12, p. 279. | FNA vol. 12, p. 321. | ||||
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Poinsettia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Chamaesyce ocellata | Poinsettia dentata | ||||
Name authority | Durand & Hilgard: Pl. Heermann., 46. (1854) | Michaux: Fl. Bor.-Amer. 2: 211. (1803) | ||||
Web links |
|