Euphorbia ophthalmica |
Euphorbia missurica |
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Florida hammock sandmat |
Missouri spurge, prairie sandmat, prairie spurge |
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Habit | Herbs, usually annual, rarely short-lived perennial, with slender to slightly thickened taproot. | Herbs, annual, with taproot. |
Stems | usually prostrate, rarely ascending, 6–22 cm, usually both strigillose and hirsute. |
erect or ascending, 10–60(–100) cm, glabrous, sometimes ± glaucous. |
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. |
opposite; stipules usually distinct, occasionally connate basally on one or both sides of stem, linear to triangular-subulate, usually deeply and irregularly fringed or lobed, rarely entire, 0.7–1.5 mm, glabrous; petiole 1–3 mm, glabrous; blade linear to narrowly oblong or narrowly lanceolate-oblong, (4–)8–30 × 3–7 mm, base symmetric or subsymmetric (usually narrower leaves), or slightly asymmetric and angled or short-tapered (wider leaves), margins entire, occasionally ± revolute, apex rounded to truncate, occasionally emarginate or mucronulate, abaxial surface pale green, adaxial surface light to bright green, both surfaces glabrous; venation obscure. |
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. |
broadly campanulate, 1.2–1.8 × 1.7–1.9 mm, glabrous; glands 4, yellowish green, broadly oblong to nearly circular, cupped or folded, 0.3–0.6 × 0.3–0.7 mm; appendages white or ± pinkish tinged, ovate to oblong-ovate, 0.4–2.5 × 1.1–1.7 mm, distal margin entire or slightly crenate or emarginate at tip. |
Staminate flowers | 2–8. |
24–60. |
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 0.5–1.4 mm, 2-fid 1/2 length. |
Capsules | ovoid, 1–1.2 × 1–1.3 mm, strigillose; columella 0.7–1.1 mm. |
broadly ovoid-globose, 1.9–2.5 × 2–2.5(–3) mm, glabrous; columella 1.8–2.1 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. |
mottled whitish to brown, ovoid to broadly ovoid-triangular, bluntly 3-angled in cross section, 1.5–2 × 1.1–1.4 mm, smooth or slightly wrinkled. |
Cyathia | in dense, terminal, capitate glomerules, with reduced, bractlike leaves subtending cyathia; peduncles 0–0.8 mm. |
solitary or in small, cymose clusters these occasionally subtended by reduced, bractlike leaves at distal nodes or on congested, axillary branches; peduncle 1–5(–11) mm. |
Euphorbia ophthalmica |
Euphorbia missurica |
|
Phenology | Flowering and fruiting year-round. | Flowering and fruiting late spring–late summer. |
Habitat | Hammock forests, disturbed areas in lawns, roadsides. | Glades, ledges, bluff tops (usually calcareous), dry upland forest margins, sandy or disturbed areas. |
Elevation | 0–200 m. (0–700 ft.) | 50–1500 m. (200–4900 ft.) |
Distribution |
AR; CA; FL; GA; LA; MO; PA; Mexico; Central America; South America; West Indies [Introduced in Europe] |
AR; CO; IA; KS; MO; MT; ND; NE; NM; OK; SD; TX; WY
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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 missurica is similar to the western E. parryi but has a more upright growth habit and more conspicuous involucral gland appendages. Native occurrences have been documented from Minnesota (last collected in Ottertail County in 1936), but it appears to have been extirpated from that state due to habitat loss to agriculture. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 280. | FNA vol. 12, p. 278. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce ophthalmica, E. hirta var. procumbens, E. pilulifera var. procumbens | Chamaesyce missurica, E. missurica var. intermedia, E. petaloidea var. intermedia |
Name authority | Persoon: Syn. Pl. 2: 13. (1806) | Rafinesque: Atlantic J. 1: 146. (1832) |
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