Euphorbia oblongata |
Euphorbia simulans |
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Balkan spurge, egg-leaf spurge, oblong spurge |
mimicking sandmat, similar spurge |
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Habit | Herbs, perennial, with woody taproot. | Herbs, annual or short-lived perennial, with usually slender, occasionally slightly thickened, rootstock. |
Stems | erect, unbranched or densely branching, 80 cm, often densely villous (especially young stems and pleiochasial branches). |
prostrate to reclining, 5–40 cm, glabrous. |
Leaves | petiole absent; blade oblong to narrowly obovate or lanceolate, 15–70 × 6–25 mm, base rounded or truncate, margins finely serrulate, apex obtuse, mucronulate, surfaces glabrous; venation inconspicuously pinnate, midvein prominent. |
opposite; stipules distinct, subulate, 0.5–0.7 mm, glabrous; petiole 0.7–1.3 mm, glabrous; blade orbiculate, oval, to shortly oblong, 1–3.2 × 1.5–5 mm, base subsymmetric, rounded, margins entire, apex usually rounded, occasionally emarginate, surfaces glabrous; venation obscure, only midvein conspicuous. |
Involucre | cupulate to slightly turbinate, 1.5–2.5 × 1.3–1.5 mm, glabrous; glands 2–3, elliptic, 0.6–0.8 × 0.8–1.2 mm; horns absent. |
turbinate to campanulate, 0.8–1.2 × 0.7–1 mm, glabrous; glands 4, red to purple, slightly concave, elliptic, 0.2–0.3 × 0.4–0.5 mm; appendages absent. |
Staminate flowers | 15–40. |
15–36. |
Pistillate flowers | ovary glabrous; styles 1.5–2 mm, 2-fid. |
ovary glabrous; styles 0.2–0.3 mm, 2-fid nearly entire length. |
Capsules | globose, 3–4.5 × 3–4.5 mm, slightly 3-lobed; cocci rounded, verrucose-tuberculate, glabrous; columella 2.5–3.3 mm. |
broadly ovoid, 1.3–1.8 × 1.5–2 mm, glabrous; columella 1.1–1.4 mm. |
Seeds | brown, ovoid, 2.4–2.6 × 1.3–2 mm, smooth, caruncle reniform, 0.2–0.3 × 0.8–0.9 mm. |
whitish, reddish brown beneath coat, oblong, 4-angled in cross section, 1.5–2 × 1.3–1.8 mm, with 5–7 faint transverse ridges or wrinkles. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 2–3 times 2–4-branched; pleiochasial bracts ovate, similar in size to distal leaves; dichasial bracts distinct, ovate to suborbiculate, base truncate or rounded, margins entire or finely denticulate, apex obtuse, sometimes mucronulate; axillary cymose branches 0–4. |
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Cyathia | peduncle 1–5 mm. |
solitary at distal nodes; peduncle 0.3–0.7 mm. |
2n | = 28. |
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Euphorbia oblongata |
Euphorbia simulans |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting year-round. |
Habitat | Waste areas, disturbed sites, roadsides, fields, pastures. | Desert scrub, mountains, hills, canyons, arroyos, flats, roadsides, clay, sandy, gravelly, and rocky soils. |
Elevation | 30–900 m. (100–3000 ft.) | 600–1300 m. (2000–4300 ft.) |
Distribution |
CA; OR; WA; s Europe [Introduced in North America]
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TX; Mexico (Chihuahua, Coahuila) |
Discussion | Euphorbia oblongata is listed as a noxious weed by the states of California, Oregon, and Washington. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia simulans, which in the flora area is known only from Brewster, Hudspeth, and Presidio counties, is difficult to distinguish in the field from the sympatric E. theriaca var. theriaca, because they are mainly distinguished by seed morphology. The latter has smaller seeds with (two or) three (or four) prominent transverse ridges, whereas E. simulans has larger seeds that are slightly wrinkled. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 289. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalus oblongatus | E. polycarpa var. simulans, Chamaesyce simulans |
Name authority | Grisebach: Spic. Fl. Rumel. 1: 136. (1843) | (L. C. Wheeler) Warnock & M. C. Johnston: SouthW. Naturalist 5: 170. (1960) |
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