Euphorbia ipecacuanhae |
Euphorbia bilobata |
|
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American ipecac, Carolina ipecac, ipecac spurge |
black-seed spurge |
|
Habit | Herbs, perennial, with deep, stout rootstock. | Herbs, annual, with slender 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, branched, 10–35 cm, glabrous or strigillose (especially when young and around nodes). |
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. |
opposite proximally, alternate distally; stipules 0.1–0.2 mm; petiole 1–4(–6) mm, glabrous, sericeous or strigillose; blade linear to narrowly elliptic, 8–52 × 2–7 mm, base attenuate, margins entire, ciliate-strigose, apex acute, abaxial surface sparsely strigillose to sericeous, adaxial surface usually glabrous; venation obscure, only midvein conspicuous. |
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. |
obconic, 0.9–1.5 × 0.9–1.3 mm, strigillose to pilose; glands 5, yellow or pink, U-shaped, 0.2–0.3 × 0.4–0.5 mm; appendages greenish, white, or pink, forming narrow rim around gland, or ovate, oblong, or obovate and usually 2-fid, rarely rudimentary, 0.2–1.4 × 0.2–0.6 mm, entire. |
Staminate flowers | 10–20. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
ovary glabrous, puberulent, strigillose, or pilose; styles 0.5–0.8 mm, 2-fid 1/3–1/2 length. |
Capsules | globose, 2.3–3.4 × 3.5–4.2 mm, glabrous; columella 3–3.1 mm. |
oblate, 1.5–2.6 × 2.1–3.3 mm, glabrous or puberulent, strigillose, or pilose; columella 1.2–2.1 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 to grayish black, narrowly ovoid, 3- or 4-angled in cross section, sometimes obscurely so, 1.3–1.9 × 1–1.4 mm, tuberculate, often with shallow depressions; caruncle absent. |
Cyathia | usually in terminal dichasia, sometimes pleiochasia; peduncle 10–50(–70) mm, glabrous. |
solitary at distal nodes or in weakly defined cymes or dichasia, dichasial bracts and distal stem leaves wholly green; peduncle 0.5–3.6 mm, strigillose. |
2n | = 32. |
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Euphorbia ipecacuanhae |
Euphorbia bilobata |
|
Phenology | Flowering and fruiting early spring–early summer. | Flowering and fruiting spring–fall. |
Habitat | Pine and pine-oak savannas, pine-oak sand hills, turkey oak scrub, open sand habitats. | Sandy and rocky soils on slopes and canyon bottoms in pine-juniper woodlands, oak woodlands, grasslands. |
Elevation | 0–150 m. (0–500 ft.) | 1400–2600 m. (4600–8500 ft.) |
Distribution |
CT; DC; DE; GA; MD; NC; NJ; NY; PA; SC; VA
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AZ; NM; TX; Mexico (Chihuahua, Durango, Sonora)
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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.) |
In Texas, Euphorbia bilobata is known only from Jeff Davis County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 247. | FNA vol. 12, p. 243. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | E. arundelana, Tithymalopsis ipecacuanhae | |
Name authority | Linnaeus: Sp. Pl. 1: 455. (1753) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 190. (1859) |
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