Euphorbia graminea |
Euphorbia meganaesos |
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grassleaf spurge |
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Habit | Herbs, usually annual, rarely perennial, with slender, rarely tuberous, taproot. | Herbs, annual, with taproot. |
Stems | erect or ascending, branched, 30–80(–110) cm, strigillose or glabrescent, sharply angled. |
prostrate to ascending, drooping at tips, 15–30 cm, glabrous. |
Leaves | usually alternate, sometimes some opposite; stipules usually 0.2–0.5 mm, rarely rudimentary; petiole 0.4–5.9 mm, strigillose; blade ovate, elliptic, linear-elliptic, or oblong, 10–83 × 3–39 mm, base attenuate, rounded, or cuneate, margins entire, apex acute or obtuse, surfaces strigillose; venation occasionally obscure on narrow leaves, midvein conspicuous. |
opposite; stipules distinct, divided nearly to base into linear-filiform segments, 1–2 mm, glabrous; petiole 0.5–1.3 mm, glabrous; blade narrowly oblong to oblong-obovate, often ± falcate, 5–16 × 1–4.5 mm, base subsymmetric to strongly oblique, margins sparsely spinulose-serrulate, apex rounded or broadly acute, abaxial surface pale grayish green, adaxial surface sometimes with reddish streak along midvein, both surfaces not papillate, glabrous; 3–5-veined at base. |
Involucre | campanulate or obconic, 1–1.8 × 0.8–1.7 mm, glabrous or strigillose toward rim; glands (1–)2–4, yellow to greenish, elliptic or oblong, 0.1–0.3 × 0.2–0.4 mm; appendages white to tinged purple, ovate and often hoodlike or forming narrow rim around distal margin of gland, 0.3–1.6 × 0.4–0.9 mm, entire. |
obconic, 0.7–0.9 × 0.4–0.6 mm, glabrous; glands 4, green to yellow-green, subequal, oblong, 0.1–0.2 × 0.2–0.3 mm; appendages white to reddish tinged, lunate to oblong, 0.1–0.3 × 0.3–0.5 mm (2 ± 2 times longer than other 2), entire or coarsely toothed. |
Staminate flowers | 30–40. |
2–5. |
Pistillate flowers | ovary glabrous; styles 0.7–1 mm, 2-fid from 1/2 to nearly entire length. |
ovary glabrous; styles 0.2–0.3 mm, 2-fid at apex to nearly 1/2 length. |
Capsules | ovoid-oblate, 2.5–3 × 3–3.5 mm, glabrous; columella 1.6–1.9 mm. |
ovoid, cocci not elongated nor terminating in empty portion, 1.5 × 1.7 mm, glabrous; columella 1.3 mm. |
Seeds | gray, brown, or nearly black, ovoid, circular or weakly angled in cross section, 1.5–1.7 × 1.3–1.5 mm, coarsely tuberculate with longitudinal rows of shallow pits; caruncle absent or punctiform, 0.1–0.2 mm. |
reddish brown to brown, pyramidal to oblong-ovoid, weakly 4-angled in cross section, 0.9–1 × 0.7 mm, minutely beaded, with 3–4 broad, rounded, transverse ridges that do not interrupt abaxial keel. |
Cyathia | in usually terminal, rarely axillary, dichasia, distal dichasial bracts often white; peduncle 0.4–4.5 mm (to 15 mm at first node of inflorescence), glabrous. |
solitary at distal nodes or on congested, axillary branches; peduncle 0.1–0.4 mm. |
Euphorbia graminea |
Euphorbia meganaesos |
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Phenology | Flowering and fruiting year-round. | Flowering and fruiting late spring–late summer. |
Habitat | Disturbed, weedy, or urban areas. | Sandy beaches, edges of marshes, coastal prairies, roadsides. |
Elevation | 0–500 m. (0–1600 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AR; CA; FL; LA; TX; Mexico; Central America; South America [Introduced in North America; introduced also in West Indies, Asia, Pacific Islands]
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LA; TX |
Discussion | Euphorbia graminea occurs natively from northern South America to northern Mexico. The species is a variable and taxonomically complex entity whose boundaries are not well defined and are in need of further study. Euphorbia graminea is often weedy and has recently become established in warmer areas of the southern United States, where it will likely become more common in the future. In recent years, a cultivar of E. graminea has found considerable horticultural success and is marketed under the trade name "Diamond Frost." (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia meganaesos is known only from coastal areas of southern Louisiana and adjacent Texas. This species was often considered conspecific with E. maculata in the past, but it differs from that species in being entirely glabrous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 246. | FNA vol. 12, p. 276. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Name authority | Jacquin: Select. Stirp. Amer. Hist., 151. (1763) | Featherman: Rep. (Annual) Board Supervisors Louisiana State Seminary Learning Military Acad. 1870: 71, 105. (1871) |
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