Euphorbia helioscopia |
Euphorbia serrula |
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euphorbe réveille-matin, mad woman's milk, summer spurge, sun spurge, wart spurge, wartweed |
sawtooth sandmat |
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Habit | Herbs, annual, with taproot. | Herbs, annual, with slender taproot. |
Stems | erect, unbranched or branched, 5–45 cm, usually glabrous or sparsely pilose. |
prostrate or ascending, 5–20 cm, usually pilose to villous, rarely glabrate. |
Leaves | petiole absent or to 0.5 mm; blade obovate-spatulate, 4–40 × 2–25 mm, base cuneate, attenuate, or auriculate, margins serrulate, apex rounded, surfaces glabrous; venation pinnate, midvein prominent. |
opposite; stipules usually distinct, rarely connate at base, triangular or laciniate into subulate segments, 1–1.8 mm, glabrous; petiole 0.3–0.8 mm, glabrous or villous; blade oblong, ovate, or elliptic, sometimes falcate, 3–11 × 2–5 mm, base asymmetric, rounded to hemicordate, margins sharply serrate to serrulate, usually with conspicuous teeth at base of leaf, apex usually obtuse, rarely acute, surfaces frequently with red blotch in center, not papillate, sparsely pilose to glabrate; only midvein conspicuous. |
Involucre | cupulate, 1.5–2 × 0.7–1.1 mm, glabrous; glands 4, elliptic, 0.2–0.5 × 0.5–1 mm; horns absent. |
obconic, 0.8–1.1 × 0.8–1 mm, glabrous; glands 4, greenish yellow, usually reniform to elliptic, rarely circular, 0.1 × 0.1–0.2 mm; appendages usually white, rarely light pink, orbiculate, 0.1–0.3 × 0.2–0.4 mm, distal margin entire or crenulate. |
Staminate flowers | 10–15. |
7–15. |
Pistillate flowers | ovary glabrous; styles 0.7–1 mm, 2-fid. |
ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 length. |
Capsules | depressed-globose, 2.5–4 × 3.2–4.2 mm, clearly 3-lobed; cocci rounded, smooth, glabrous; columella 0.9–1.1 mm. |
oblate, cocci not elongated nor terminating in empty portion, 2–2.6 × 3.2–3.7 mm, glabrous; columella 1.7–2.1 mm. |
Seeds | dark brown to blackish, subovoid, 1.6–2.2 × 1.5–1.9 mm, reticulate; caruncle elliptic, 0.9–1.1 × 0.4–0.5 mm. |
white to light brown, broadly ellipsoid to ovoid, 3–4-angled in cross section, 1.5–1.8 × 1.1–1.3(–1.5) mm, smooth to minutely rugulose or with scattered small depressions. |
Cyathial | arrangement: terminal pleiochasial branches (3–)5, each 1–2 times 2-branched; pleiochasial bracts obovate, wider than distal leaves; dichasial bracts distinct, obovate or rhombic, ± oblique, base rounded, truncate, or attenuate, margins serrulate, apex rounded; axillary cymose branches 0. |
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Cyathia | peduncle 0.2–1 mm. |
solitary at distal nodes; peduncle 0.4–1.8(–2.3) mm. |
Euphorbia helioscopia |
Euphorbia serrula |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Roadsides, waste places. | Desert scrub, with creosote bush, grasslands with mesquite and yucca, rarely in ponderosa pine woodlands, often sandy substrates. |
Elevation | 0–1400 m. (0–4600 ft.) | 300–1900 m. (1000–6200 ft.) |
Distribution |
CA; CT; DC; DE; GA; ID; IL; LA; MA; MD; ME; MI; MT; NC; NH; NJ; NY; OH; OR; PA; SC; TN; TX; VA; VT; WA; WI; WY; AB; BC; NB; NF; NS; ON; PE; QC; SK; Europe; Asia; n Africa [Introduced in North America; introduced also in South America (Argentina, Chile)]
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AZ; NM; TX; Mexico
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Discussion | Euphorbia helioscopia was collected once in Minnesota in the late 1800s but apparently did not become established there. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In Mexico, Euphorbia serrula is found from Chihuahua and Coahuila south to Puebla. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 303. | FNA vol. 12, p. 288. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Galarhoeus helioscopius, Tithymalus helioscopius | Chamaesyce serrula |
Name authority | Linnaeus: Sp. Pl. 1: 459. (1753) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 188. (1859) |
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