Euphorbia ophthalmica |
Euphorbia polyphylla |
|
---|---|---|
Florida hammock sandmat |
lesser Florida spurge |
|
Habit | Herbs, usually annual, rarely short-lived perennial, with slender to slightly thickened taproot. | Herbs, perennial, with spreading rootstock. |
Stems | usually prostrate, rarely ascending, 6–22 cm, usually both strigillose and hirsute. |
erect or ascending, branched, solitary, few, or occasionally densely clumped, previous year's dead stems not persistent, 18–33 cm, glabrous. |
Leaves | opposite; stipules distinct, subulate-filiform, undivided or divided into 2–4 narrowly triangular to linear-subulate segments, no dark, circular glands at base of stipules, 0.9–1.5 mm, pilose or strigillose; petiole 0.3–1.2 mm, glabrescent, strigillose, or sericeous; blade usually ovate or oblong, rarely subrhombic, 4–13 × 3–7 mm, base asymmetric, one side usually angled and other side rounded, margins coarsely serrulate, apex acute, surfaces often with red spot in center, strigillose or sericeous, or adaxial surface glabrescent; 3-veined from base. |
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. |
Involucre | obconic, 0.5–0.7 × 0.4–0.6 mm, strigillose; glands 4, yellow green to pink, circular to slightly oblong, 0.1–0.2 × 0.1–0.2 mm; appendages absent or white to pink, forming thin rim around edge of gland or oblong, 0.1–0.2 × 0.1–0.3 mm, distal margin entire or shallowly lobed. |
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. |
Staminate flowers | 2–8. |
20–25. |
Pistillate flowers | ovary strigillose, often canescent when young; styles 0.1–0.3 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous; styles 0.6–1 mm, 2-fid at apex. |
Capsules | ovoid, 1–1.2 × 1–1.3 mm, strigillose; columella 0.7–1.1 mm. |
globose, 2.3–2.8 × 4.3–5.1 mm, glabrous; columella 2.5–3.2 mm. |
Seeds | orange-brown to pinkish, narrowly ovoid, 4-angled in cross section, 0.7–0.9(–1.1) × 0.5 mm, usually rugulose, with 3–6 faint, low, transverse ridges, rarely almost smooth. |
ashy gray, ovoid, 2.9 × 2 mm, with obscure shallow depressions; caruncle absent. |
Cyathia | in dense, terminal, capitate glomerules, with reduced, bractlike leaves subtending cyathia; peduncles 0–0.8 mm. |
in terminal dichasia or pleiochasia; peduncle 2–6 mm (to 20 mm for central cyathium), glabrous. |
Euphorbia ophthalmica |
Euphorbia polyphylla |
|
Phenology | Flowering and fruiting year-round. | Flowering and fruiting late spring–late fall. |
Habitat | Hammock forests, disturbed areas in lawns, roadsides. | Open sand and pine savannas. |
Elevation | 0–200 m. (0–700 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AR; CA; FL; GA; LA; MO; PA; Mexico; Central America; South America; West Indies [Introduced in Europe] |
FL
|
Discussion | Euphorbia ophthalmica is a weedy species distributed throughout the Neotropics. It is also adventive in the Old World. Whether it is indeed native to the southeastern United States is questionable; it is introduced in Arkansas, California, Missouri, and Pennsylvania and likely occurs also in other states. Although sometimes treated as E. hirta var. procumbens, E. ophthalmica appears sufficiently distinct to justify recognition at the rank of species, differing primarily by its mostly prostrate growth form, smaller leaves, and strictly terminal clusters of cyathia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 12, p. 280. | FNA vol. 12, p. 250. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | Chamaesyce ophthalmica, E. hirta var. procumbens, E. pilulifera var. procumbens | Tithymalopsis polyphylla |
Name authority | Persoon: Syn. Pl. 2: 13. (1806) | Engelmann ex Chapman: Fl. South. U.S. ed. 2, repr. 2, 694. (1892) |
Web links |