Euphorbia polyphylla |
Euphorbia arizonica |
|
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lesser Florida spurge |
Arizona sandmat, Arizona spurge |
|
Habit | Herbs, perennial, with spreading rootstock. | Herbs, annual or short-lived perennial, with slender to slightly thickened taproot. |
Stems | erect or ascending, branched, solitary, few, or occasionally densely clumped, previous year's dead stems not persistent, 18–33 cm, glabrous. |
erect to ascending, 10–30 cm, uniformly pilose with glistening hairs. |
Leaves | alternate; stipules to 0.1 mm; petiole minute or absent; blade linear to filiform, 10–20 × 0.8–1.5(–4) mm, base cuneate, margins entire, often involute, apex rounded, surfaces glabrous; venation usually obscure, midvein visible at base of wider leaves. |
opposite; stipules distinct, deltate, (0–)0.1 mm, glabrous or with few scattered hairs; petiole 0.4–1.5 mm, pilose with glistening hairs; blade usually ovate, rarely elliptic, 3–11 × 2–7 mm, base asymmetric, one side cuneate to rounded, other side rounded to strongly cordate, margins entire, apex obtuse or acute, surfaces pilose with glistening hairs; 3-veined from base but usually only midvein conspicuous. |
Involucre | campanulate, 1.2–2 × 1.3–1.8 mm, glabrous or strigose on distal extreme; glands 5, red, elliptic, 0.5 × 1 mm; appendages white, orbiculate, 0.5–0.8 × 1.3–1.5 mm, erose. |
urceolate, 1.1–1.3 × 0.5–0.9 mm, glabrous or pilose with glistening hairs; glands 4, dark maroon, usually oblong to reniform, rarely almost circular, 0.2 × 0.2–0.4 mm; appendages white to pink, oblong, flabellate, oblong, or elliptic, 0.3–0.6 × 0.6–0.9 mm, distal margin entire or crenulate. |
Staminate flowers | 20–25. |
5–12. |
Pistillate flowers | ovary glabrous; styles 0.6–1 mm, 2-fid at apex. |
ovary pilose, styles 0.5–0.6 mm, 2-fid 1/2 length. |
Capsules | globose, 2.3–2.8 × 4.3–5.1 mm, glabrous; columella 2.5–3.2 mm. |
broadly ovoid to subglobose, 1.4–1.8 mm diam., pilose; columella 1.1–1.4 mm. |
Seeds | ashy gray, ovoid, 2.9 × 2 mm, with obscure shallow depressions; caruncle absent. |
gray to light brown, ovoid, 4-angled in cross section, 0.9–1.1 × 0.5–0.6 mm, rugose with 2–5 irregular transverse ridges that sometimes pass through abaxial keel. |
Cyathia | in terminal dichasia or pleiochasia; peduncle 2–6 mm (to 20 mm for central cyathium), glabrous. |
solitary at distal nodes; peduncle 0.7–3.6 mm. |
Euphorbia polyphylla |
Euphorbia arizonica |
|
Phenology | Flowering and fruiting late spring–late fall. | Flowering and fruiting year-round in response to sufficient moisture. |
Habitat | Open sand and pine savannas. | Washes and rocky slopes, sometimes on limestone, desert scrub communities often with creosote-bush, riparian forests, mesquite woodlands, oak chaparral. |
Elevation | 0–10 m. (0–0 ft.) | 100–1400 m. (300–4600 ft.) |
Distribution |
FL
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AZ; CA; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, Sonora)
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Discussion | Euphorbia polyphylla is endemic to sandy habitats in the southern half of peninsular Florida. The species has been reported from coastal Louisiana, but whether those plants represent native occurrences or plantings is unclear (R. D. Thomas and C. M. Allen 1993–1998, vol. 2). The Florida populations are here recognized as the only native occurrences. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia arizonica is distinctive and easily recognized by its glistening, translucent hairs that appear somewhat glutinous and are most apparent on the stems. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 250. | FNA vol. 12, p. 260. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalopsis polyphylla | Chamaesyce arizonica |
Name authority | Engelmann ex Chapman: Fl. South. U.S. ed. 2, repr. 2, 694. (1892) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 186. (1859) |
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