Euphorbia ipecacuanhae |
Euphorbia exstipulata |
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American ipecac, Carolina ipecac, ipecac spurge |
square-seed spurge, squareseed or Clark Mountain spurge |
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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, 5–26 cm, uniformly puberulent to hispidulous or glabrous; branches arcuate. |
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; petiole 1–3 mm, often indistinct, glabrous or puberulent; blade linear to narrowly elliptic or ovate, 14–42 × 3–28 mm, base attenuate, margins coarsely serrate, occasionally revolute, apex acute to obtuse, abaxial surface sparsely hispidulous to strigillose, adaxial surface glabrous; 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. |
turbinate to campanulate, 1.1–1.5 × 1–1.3 mm, glabrous, pilose or puberulent; involucral lobes divided into several linear lobes; glands 4(–5), yellow to pink, sessile and broadly attached, 0.2 × 0.3–0.4 mm, opening oblong to nearly circular, glabrous; appendages usually petaloid, white to pink, ovate to trapezoidal, occasionally absent, not incurved and covering glands, 0.2–0.4 × 0.3–0.8 mm, entire, undulate, or conspicuously divided into triangular segments, glabrous. |
Staminate flowers | 10–20. |
10–12. |
Pistillate flowers | ovary glabrous; styles 0.4–0.8 mm, 2-fid at apex. |
ovary puberulent on keels, styles 0.8–1.1 mm, 2-fid 1/2 to nearly entire length. |
Capsules | globose, 2.3–3.4 × 3.5–4.2 mm, glabrous; columella 3–3.1 mm. |
broadly depressed-oblong to ovoid, 2.7–3.3 × 3.1–3.9 mm, puberulent (with appressed hairs usually concentrated on keels); columella 1.9–2.5 mm. |
Seeds | white or brown, ovoid, 2.3–2.5 × 1.5 mm, angular, with 5 longitudinal ridges, shallowly and irregularly pitted; caruncle absent. |
white to gray or light brown, ovoid, bluntly 4-angled in cross section, 1.9–2.5 × 1.4–1.7 mm, tuberculate, often with 2 transverse ridges; caruncle 0.1 × 0.2 mm. |
Cyathia | usually in terminal dichasia, sometimes pleiochasia; peduncle 10–50(–70) mm, glabrous. |
peduncle 1–1.9 mm. |
Cyathial | arrangement: terminal cymose or dichasial branches usually 1–2, occasionally reduced to monochasia, 1–2-branched; pleiochasial bracts 2–4, often whorled, wholly green or paler green at base, similar in shape and size to distal leaves or slightly narrower; dichasial bracts similar in shape to distal leaves but smaller or highly reduced. |
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Euphorbia ipecacuanhae |
Euphorbia exstipulata |
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Phenology | Flowering and fruiting early spring–early summer. | Flowering and fruiting summer–fall. |
Habitat | Pine and pine-oak savannas, pine-oak sand hills, turkey oak scrub, open sand habitats. | Desert scrub, grasslands, mesquite savannas, oak and oak-juniper woodlands. |
Elevation | 0–150 m. (0–500 ft.) | 800–2000 m. (2600–6600 ft.) |
Distribution |
CT; DC; DE; GA; MD; NC; NJ; NY; PA; SC; VA
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AZ; CA; NM; TX; UT; WY; Mexico (Chihuahua, Coahuila, Durango, Guanajuato, San Luis Potosí, Sonora, Zacatecas)
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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.) |
Euphorbia exstipulata is native from Texas to California and northern Mexico. The species was found once in the late nineteenth century in Wyoming but has not been re-collected there. Broad-leaved plants have been segregated as var. lata, but the variation in leaf shape is continuous and no varieties are formally recognized here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 247. | FNA vol. 12, p. 322. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | E. arundelana, Tithymalopsis ipecacuanhae | E. exstipulata var. lata |
Name authority | Linnaeus: Sp. Pl. 1: 455. (1753) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 189. (1859) |
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