Euphorbia eriantha |
Euphorbia velleriflora |
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beetle spurge |
Caliche sandmat |
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Habit | Herbs, annual or perennial, with slender to thick, woody taproot. | Herbs, perennial, with strongly thickened and lignified rootstock. |
Stems | erect to ascending, 10–75 cm, glabrous or with scattered appressed hairs (especially near nodes); branches arcuate. |
prostrate, usually mat-forming, terete to slightly flattened and winged, to 30 cm, villous to pilose. |
Leaves | alternate; petiole 0.1–0.4 mm, often indistinct, glabrous or sparsely pilose to shortly sericeous; blade linear to linear-elliptic, 20–55 × 1–3 mm, base attenuate, margins entire or with 2–4 inconspicuous teeth near apex, apex acute, abaxial surface pilose to shortly sericeous, adaxial surface usually glabrous, rarely pilose to shortly sericeous; only midvein conspicuous. |
opposite; stipules distinct or connate at base, 2-fid to laciniate into 2–5 linear to subulate divisions, 0.5–1(–2) mm, glabrous or villous; petiole 0.5–2 mm, villous; blade usually ovate to oblong, rarely suborbiculate, 5–13 × 4–8 mm, base asymmetric, hemicordate, margins serrulate, apex obtuse, surfaces villous; 3-veined from base, usually only midvein conspicuous. |
Involucre | obconic, 2.1–2.6 × 1.3–2 mm, canescent; involucral lobes triangular, obscured by hairs; glands (2–)4–5, green to maroon, color often obscured by hairs, sessile and broadly attached, 0.5–0.6 × 0.5–0.6 mm, opening oblong to nearly circular, densely canescent; appendages petaloid, whitish, hoodlike, incurved and covering glands, 0.5–1 × 0.5–0.8 mm, divided into 5–12 fringed, subulate segments, densely canescent. |
turbinate, 0.9–1.4 × 0.7–1.1 mm, villous; glands 4, pink, oblong to reniform, 0.1–0.2 × 0.3–0.4 mm; appendages white to pink, flabellate, ovate, or oblong, 0.3–0.5 × 0.4–0.7 mm, distal margin entire, crenulate, or erose, often puberulent-ciliate. |
Staminate flowers | 20–25. |
8–12. |
Pistillate flowers | ovary canescent; styles 0.9–1.5 mm, unbranched. |
ovary villous; styles 0.2–0.4(–0.5) mm, 2-fid 1/2 length. |
Capsules | oblong to ovoid, 4.4–4.9 × 3.5–4.1 mm, canescent (often with interspersed glabrescent patches); columella 3.5–3.9 mm. |
broadly ovoid, 1.5–1.9 × 1.3–1.7 mm, villous (uniformly so, but most pronounced toward base and along keels); columella 1.2–1.4 mm. |
Seeds | mottled black and gray or light brown, oblong or slightly ovoid, dorsiventrally compressed in cross section, 2.8–4.1 × 2–2.4 mm, irregularly pitted and tuberculate; caruncle 0.4–0.8 × 0.6–1.1 mm. |
white to gray or pink, narrowly pyramidal-ovoid, 4-angled in cross section, 1.1–1.3 × 0.4–0.6 mm, rugulose with shallow depressions separated by inconspicuous transverse ridges. |
Cyathial | arrangement: terminal cymose branches 1, 1–2-branched; pleiochasial bracts 2–3, opposite or whorled, wholly green, similar in shape and size to distal leaves; dichasial bracts similar in shape to distal leaves or often highly reduced. |
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Cyathia | peduncle 1–1.9 mm. |
solitary at distal nodes or at nodes of leafy, congested, axillary branches; peduncle 1–1.5(–2.5) mm. |
Euphorbia eriantha |
Euphorbia velleriflora |
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Phenology | Flowering and fruiting year-round in response to sufficient rainfall. | Flowering and fruiting summer. |
Habitat | Desert scrub on rocky slopes and along washes. | Disturbed habitats, particularly roadsides, grasslands, live oak-thorn scrub. |
Elevation | 60–800 m. (200–2600 ft.) | 50–80 m. (200–300 ft.) |
Distribution |
AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora)
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TX; Mexico; Central America (Guatemala) [Introduced in North America] |
Discussion | Euphorbia velleriflora is native and widespread from northern Mexico to Guatemala. The species is apparently a recent introduction in southern Texas (W. R. Carr and M. H. Mayfield 1993), as the first records are from the 1990s. It is also expected in southern Arizona due to the presence of collections made a few kilometers south of the border in the Mexican state of Sonora. Euphorbia velleriflora is very similar to E. stictospora, and the two are sometimes confused. The two can be readily distinguished on the basis of their styles: unbranched in E. stictospora and 2-fid in E. velleriflora. Also, the involucral gland appendages of E. velleriflora are ciliate with short hairs, whereas those of E. stictospora are glabrous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 321. | FNA vol. 12, p. 292. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Anisophyllum velleriflorum, Chamaesyce velleriflora | |
Name authority | Bentham: Bot. Voy. Sulphur, 51. (1844) | (Klotzsch & Garcke) Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 40. (1862) |
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