Euphorbia cuphosperma |
Euphorbia antisyphilitica |
|
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hairy-fruit spurge |
candelilla, wax plant |
|
Habit | Herbs, annual, with taproot. | Shrubs, with much-branched, fleshy rootstock. |
Stems | erect, 13–20 cm, both pilose to villous and densely strigillose; branches ± straight. |
erect, few branched, 25–50(–100) cm, glabrous or puberulent, pencil-like, in age covered with flaky, exfoliating layer of wax. |
Leaves | usually opposite, occasionally alternate at distal nodes; petiole 3–15 mm, pilose; blade narrowly to broadly elliptic, or lanceolate to ovate, 30–80 × 10–15 mm, base cuneate to rounded, margins coarsely crenate-dentate, strigose, revolute to nearly flat, apex broadly acute to acuminate, or obtuse, abaxial surface pilose, adaxial surface sparsely strigose-hirsute; venation pinnate, midvein prominent. |
alternate usually caducous, sometimes persisting; stipules 0.4–0.5 mm; petiole absent; blade ovate to deltate-subulate, 2.5–4 × 1 mm, thick, fleshy, base usually rounded and swollen, rarely cuneate, margins entire, apex acute, surfaces puberulent, adaxial sometimes canescent; venation inconspicuous. |
Involucre | campanulate to slightly cylindric, 2.3 × 1.2 mm, glabrous; involucral lobes divided into several linear, smooth lobes; gland 1, yellow-green, stipitate, clavate, 1–1.2 × 0.8–0.9 mm, opening bilabiate and oblong, glabrous; appendages absent. |
campanulate, 1.6–2.2 × 1.6–1.9 mm, puberulent to canescent; glands 5, pinkish, narrowly oblong to reniform, 0.3–0.4 × 0.8–1 mm; appendages white to pink, ovate, oblong, or transversely oblong, 1.3–2.5 × 1.4–2.5 mm, usually erose, rarely entire. |
Staminate flowers | 3–5. |
50–70. |
Pistillate flowers | ovary pilose; styles 1.2 mm, 2-fid nearly entire length. |
ovary glabrous; styles 0.9–1.1 mm, 2-fid nearly entire length. |
Capsules | broadly ovoid, 2.2–3 × 1.9–2.7 mm, 3-lobed, pilose; columella 2–2.4 mm. |
oblong to ovoid, 3.9–4.2 × 3.6–3.9 mm, glabrous; columella 3.1–3.3 mm. |
Seeds | gray-brown to pale gray, pyramidally ovoid, angular in cross section, 2.3–2.6 × 2.4–2.6 mm, coarsely tuberculate, tubercles in 2 transverse rows; caruncle 0.2–0.4 mm. |
whitish gray, narrowly ovoid, 2.4–3.1 × 1.4–1.6 mm, irregularly rugose-tuberculate; caruncle crescent-shaped, 0.3–0.6 × 0.6–0.8 mm. |
Cyathial | arrangement: terminal pleiochasial branches usually 3, occasionally reduced to congested cyme, 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 highly reduced. |
|
Cyathia | peduncle 0.5–0.8 mm. |
in axillary congested cymes, near branch tips or solitary at distal nodes; peduncle 0–1 mm, lanulose. |
2n | = 56. |
|
Euphorbia cuphosperma |
Euphorbia antisyphilitica |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting year-round in response to sufficient rainfall. |
Habitat | Open montane and canyon forests, pinyon-juniper forests, montane grasslands, stream beds, disturbed habitats. | Desert scrub, frequently on limestone substrates. |
Elevation | 800–2000 m. (2600–6600 ft.) | 100–1200 m. (300–3900 ft.) |
Distribution |
AZ; NM; Mexico; Central America (Guatemala)
|
NM; TX; Mexico
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Discussion | Euphorbia antisyphilitica is the only pencil-stemmed species of Euphorbia occurring in the flora area. The species is characteristic of the Chihuahuan Desert scrub of Mexico from Chihuahua and Coahuila south to Hidalgo and Querétaro, and barely enters into the United States in southern New Mexico (Doña Ana and Lincoln counties) and southwest (Brewster, Hudspeth, Presidio, and Terrell counties) and south (Starr and Webb counties) Texas. The stems are covered in a conspicuous coat of exfoliating wax, and the plants historically have been harvested for this product, although the practice is much less prevalent now. The specific epithet refers to its traditional medicinal use in treating sexually transmitted infections. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 319. | FNA vol. 12, p. 243. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | E. dentata var. cuphosperma, Poinsettia cuphosperma | |
Name authority | (Engelmann) Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 73. (1862) | Zuccarini: Flora 15(2, Beibl.): 58. (1832) |
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