Euphorbia hypericifolia |
Euphorbia prostrata |
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graceful sandmat, graceful spurge |
blue weed, ground spurge, prostrate sandmat, prostrate spurge or sandmat |
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Habit | Herbs, annual, with taproot. | Herbs, annual, with taproot. |
Stems | erect to ascending, 15–50 cm, glabrous. |
prostrate to decumbent, usually not mat-forming, 10–30 cm, crisped-villous to glabrate (proximally). |
Leaves | opposite; stipules connate, deltate, usually entire, sometimes laciniate-fringed at tip, 1.5–2.2 mm, glabrous; petiole 1–3 mm, glabrous; blade obliquely oblong-oblanceolate, 10–35 × 7–15 mm, base asymmetric, oblique, margins serrate or serrulate, especially toward apex, apex broadly acute, surfaces glabrous; palmately veined at base, pinnate distally. |
opposite; stipules connate (lower side) or distinct (upper side), triangular-subulate, often lacerate distally, 0.5–1 mm, short crisped-villous to glabrate; petiole 0.5–1.5 mm, usually short crisped-villous, sometimes wooly at distal nodes; blade broadly elliptic to elliptic-oblong, ovate-spatulate, or ovate, 3–11(–15) × 3–6(–8) mm, base slightly asymmetric, rounded to slightly cordate and oblique, margins serrulate at least in distal 1/2, sometimes obscurely so, apex obtuse, abaxial surface finely crisped-villous, adaxial surface usually glabrous or glabrate, sometimes sparsely crisped-villous; 3-veined from base. |
Involucre | obconic, 0.9–1.1 × 0.4–0.9 mm, glabrous; glands 4, yellow-green to brown, stipitate, subcircular, 0.2 × 0.2 mm, occasionally nearly rudimentary; appendages absent on smaller glands or white to pink, shape highly variable, usually round to ± elliptic, 0.3–0.4 × 0.5–0.7 mm, distal margin entire. |
obconic, 0.6–0.9 × 0.5 mm, crisped-villous or glabrous; glands 4, reddish, oval to oblong, 0.1 × 0.1–0.2 mm; appendages white to pink, rudimentary, 0–0.2 mm, distal margin entire or irregularly scalloped. |
Staminate flowers | (0–)2–20. |
3–6. |
Pistillate flowers | ovary glabrous; styles 0.4 mm, 2-fid 1/2 length. |
ovary densely crisped-villous; styles 0.1 mm, 2-fid nearly entire length. |
Capsules | depressed-globoid, 1.3–1.4 × 1.1–1.5 mm, glabrous; columella 1–1.1 mm. |
broadly ovoid, 1.2–2 × 1.4–1.5 mm, crisped-villous along keels and toward base, often glabrous between keels; columella 1–1.2 mm. |
Seeds | with very thin whitish mucilaginous coat over light brown testa below, ovoid-triangular, bluntly 4-angled in cross section, 0.9–1.1 × 0.5 mm, with shallow irregular depressions alternating with low, smooth ridges. |
white but with barely concealed brown surface beneath, ovoid, sharply 4-angled in cross section, abaxial faces plane to convex, adaxial faces concave, 0.8–1.1 × 0.5–0.7 mm, with several narrow, sharp, slightly irregular, transverse ridges. |
Cyathia | in dense, axillary and terminal, capitate glomerules with reduced, bractlike leaves subtending cyathia; peduncle 0.5–1.8 mm. |
solitary or in small, cymose clusters at distal nodes or on congested, axillary branches; peduncle 1–2 mm. |
2n | = 18. |
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Euphorbia hypericifolia |
Euphorbia prostrata |
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Phenology | Flowering and fruiting early spring–late fall. | Flowering and fruiting early spring–fall. |
Habitat | Open, disturbed areas, nurseries. | Disturbed areas, fields, gardens, sidewalks, sandy places, ballast piles. |
Elevation | 0–200 m. (0–700 ft.) | 0–1400 m. (0–4600 ft.) |
Distribution |
AL; AR; FL; GA; LA; OK; SC; TX; Central America; South America; West Indies [Introduced in Asia, Pacific Islands]
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AL; AR; AZ; CA; CO; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NE; NM; OH; OK; PA; SC; SD; TN; TX; UT; VA; WV; WY; Mexico; Central America; South America; West Indies [Introduced in Eurasia, Africa, Pacific Islands, Australia]
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Discussion | Euphorbia hypericifolia is native to the New World tropics, and it is most likely adventive in the flora area (where it is most widely distributed in Florida and Texas). Reports from Arizona, California, and Maryland likely represent waifs or misidentifications. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia prostrata is native to tropical America and possibly into the southern part of the flora area. It is likely adventive throughout most of the northern part of its range. It is widely naturalized throughout much of the rest of the tropics. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 272. | FNA vol. 12, p. 285. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce glomerifera, C. hypericifolia, E. glomerifera | Chamaesyce prostrata |
Name authority | Linnaeus: Sp. Pl. 1: 454. (1753) | Aiton: Hort. Kew. 2: 139. (1789) |
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