Euphorbia oblongata |
Euphorbia exserta |
|
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Balkan spurge, egg-leaf spurge, oblong spurge |
coastal sand spurge, maroon or purple sand spurge |
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Habit | Herbs, perennial, with woody taproot. | Herbs, perennial, with spreading rootstock. |
Stems | erect, unbranched or densely branching, 80 cm, often densely villous (especially young stems and pleiochasial branches). |
erect or ascending, unbranched or branched, solitary, few, or occasionally densely clumped, previous year's dead stems not persistent, 20–33 cm, usually glabrous, rarely sparsely villous, glaucescent. |
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. |
alternate; stipules less than 0.1 mm; petiole (0–)1–3 mm, glabrous; blade linear or linear-elliptic to obovate or orbiculate, proximal greatly reduced, scalelike, 15–30 × 1–20 mm, base cuneate to rounded, margins entire, apex rounded, broadly acute, or emarginate, surfaces glabrous, glaucescent; venation often obscure on narrow leaves, 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. |
usually dark red, campanulate, 1.3–1.6 × 1.4–2.1 mm, glabrous; glands 5, usually dark red, rarely greenish red, elliptic reniform, thickened, 0.3–0.5 × 0.8 mm; appendages white or green, often forming narrow rim around distal margin of gland, 0–0.2 mm, entire. |
Staminate flowers | 15–40. |
20–25. |
Pistillate flowers | ovary glabrous; styles 1.5–2 mm, 2-fid. |
ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
Capsules | globose, 3–4.5 × 3–4.5 mm, slightly 3-lobed; cocci rounded, verrucose-tuberculate, glabrous; columella 2.5–3.3 mm. |
depressed-globose, 1.8–2.5 × 3.6–4.4 mm, glabrous; columella 1.9–2.4 mm. |
Seeds | brown, ovoid, 2.4–2.6 × 1.3–2 mm, smooth, caruncle reniform, 0.2–0.3 × 0.8–0.9 mm. |
ashy white, ovoid, 2.1 × 1.3 mm, angled with 5 blunt longitudinal ridges, with shallow and irregular pits; caruncle absent. |
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. |
|
Cyathia | peduncle 1–5 mm. |
usually in terminal dichasia, sometimes pleiochasia; peduncle 6–33 mm, filiform, glabrous. |
Euphorbia oblongata |
Euphorbia exserta |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Waste areas, disturbed sites, roadsides, fields, pastures. | Xeric to dry pine-oak scrub of sand hills, pine-oak woodlands, pine-oak savannas. |
Elevation | 30–900 m. (100–3000 ft.) | 0–150 m. (0–500 ft.) |
Distribution |
CA; OR; WA; s Europe [Introduced in North America]
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FL; GA; NC; SC; VA
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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.) |
K. R. Park (1998) recognized both Euphorbia exserta and E. gracilior as distinct species, with the former known only from the holotype. However, this treatment follows M. J. Huft (1997) and treats E. gracilior as a synonym of E. exserta. Although the type of E. exserta is unusual in having greenish red (versus dark red) cyathia and glands, as well as small gland appendages, it is otherwise typical of the species as a whole, including features such as the upright habit, reddish coloration, scalelike proximal leaves, and filiform peduncles to 30 mm that are also common to plants formerly treated as E. gracilior. Euphorbia gracilis Elliott, which has sometimes been applied to E. exserta, is an illegitimate name (a later homonym of E. gracilis Loiseleur-Deslongchamps) and pertains here. The upright habit and usually dark red cyathia and glands distinguish Euphorbia exserta from the otherwise similar E. ipecacuanhae, while the glaucescent vegetative parts and smaller gland appendages readily separate E. exserta from the similar E. curtisii. Euphorbia exserta is found on the Gulf and Atlantic coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 246. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Tithymalus oblongatus | Tithymalopsis exserta, E. gracilior, T. gracilis |
Name authority | Grisebach: Spic. Fl. Rumel. 1: 136. (1843) | (Small) Coker: Pl. Life Hartsville, 88. (1912) |
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