Euphorbia ipecacuanhae |
Euphorbia roemeriana |
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American ipecac, Carolina ipecac, ipecac spurge |
Roemer's spurge |
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Habit | Herbs, perennial, with deep, stout rootstock. | Herbs, annual, with taproot. |
Stems | decumbent or slightly ascending, branched, often densely clumped, previous year's dead stems not persistent, 17–27 cm, usually glabrous, rarely sparsely villous. |
erect, occasionally decumbent at base, branched, 15–30 cm, glabrous. |
Leaves | alternate; stipules 0.1–0.2 mm; petiole (0–)1–2 mm, glabrous; blade usually linear, obovate, or oblanceolate to orbiculate, rarely filiform, proximal greatly reduced, scalelike, 15–70 × 1.5–13 mm gradually smaller proximally, base cuneate, margins entire, apex rounded, broadly acute, or emarginate, surfaces glabrous; venation occasionally obscure on smaller leaves, midvein conspicuous. |
petiole 2–5 mm; blade oblanceolate to obovate, 5–20 × 5–10 mm (larger leaves in distal portion of stem), base cuneate to attenuate, margins entire, apex rounded, surfaces glabrous; venation pinnate. |
Involucre | yellow or yellow-green, hemispheric, 1–1.2 × 2–2.4 mm, glabrous; glands 5, yellow or yellow-green, obovate or elliptic, 0.7–0.8 × 1–1.2 mm; appendages white or green, often forming narrow rim around distal margin of gland, 0–0.2 mm, entire. |
campanulate, 1.5–2 × 1–1.6 mm, glabrous; glands 4, elliptic to trapezoidal, 0.4–0.6 × 0.7–1.2 mm; horns slightly convergent, 0.1–0.3 mm. |
Staminate flowers | 10–20. |
10–12. |
Pistillate flowers | ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
ovary glabrous; styles 0.6–1 mm, 2-fid. |
Capsules | globose, 2.3–3.4 × 3.5–4.2 mm, glabrous; columella 3–3.1 mm. |
subglobose, 2–2.5 × 2.4–3 mm, slightly lobed; cocci rounded, smooth, glabrous; columella 1.5–1.8 mm. |
Seeds | white or brown, ovoid, 2.3–2.5 × 1.5 mm, angular, with 5 longitudinal ridges, shallowly and irregularly pitted; caruncle absent. |
brown, oblong-ovoid, 1.6–1.8 × 1.4–1.5 mm, with scattered, deep and broad pits; caruncle conic, reniform, 0.3–0.4 × 0.4–0.6 mm. |
Cyathia | usually in terminal dichasia, sometimes pleiochasia; peduncle 10–50(–70) mm, glabrous. |
peduncle 0–0.9 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3, 1–4 times 2-branched; pleiochasial bracts ovate to oblong, similar in size to distal leaves; dichasial bracts connate 1/2 length, reniform to semicircular, base truncate to perfoliate, margins entire, apex rounded to obtuse; axillary cymose branches 0–3. |
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Euphorbia ipecacuanhae |
Euphorbia roemeriana |
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Phenology | Flowering and fruiting early spring–early summer. | Flowering and fruiting spring. |
Habitat | Pine and pine-oak savannas, pine-oak sand hills, turkey oak scrub, open sand habitats. | Rich calcareous soils, creek canyons. |
Elevation | 0–150 m. (0–500 ft.) | 100–300 m. (300–1000 ft.) |
Distribution |
CT; DC; DE; GA; MD; NC; NJ; NY; PA; SC; VA
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TX |
Discussion | The vegetative stems of Euphorbia ipecacuanhae are often quite short in proportion to the dichasial or pleiochasial branches, thus superficially plants often appear to have mostly opposite leaves. However, careful examination of the base of the plant will reveal alternate leaves. The leaves are extremely variable in both shape and coloration, and the variation can be pronounced within a population or even on a single plant. M. J. Huft (1979) did not recognize infraspecific taxa within E. ipecacuanhae, and his treatment is followed here. This species is found on the Atlantic coastal plain. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
D. S. Correll and M. C. Johnston (1970) suggested that Euphorbia roemeriana, which is restricted to the eastern part of the Edwards Plateau, is the southern counterpart of E. commutata, to which it is morphologically very similar. However, molecular phylogenetic analyses indicate that it is most closely related to E. austrotexana and E. longicruris (J. A. Peirson et al. 2014). Euphorbia roemeriana can be distinguished from E. commutata and several of the other small, annual species of subg. Esula by its consistently connate dichasial bracts. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 247. | FNA vol. 12, p. 308. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | E. arundelana, Tithymalopsis ipecacuanhae | Tithymalus roemerianus |
Name authority | Linnaeus: Sp. Pl. 1: 455. (1753) | Scheele: Linnaea 22: 151. (1849) |
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