Euphorbia helioscopia |
Euphorbia eriantha |
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euphorbe réveille-matin, mad woman's milk, summer spurge, sun spurge, wart spurge, wartweed |
beetle spurge |
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Habit | Herbs, annual, with taproot. | Herbs, annual or perennial, with slender to thick, woody taproot. |
Stems | erect, unbranched or branched, 5–45 cm, usually glabrous or sparsely pilose. |
erect to ascending, 10–75 cm, glabrous or with scattered appressed hairs (especially near nodes); branches arcuate. |
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. |
alternate; petiole 0.1–0.4 mm, often indistinct, glabrous or sparsely pilose to shortly sericeous; blade linear to linear-elliptic, 20–55 × 1–3 mm, base attenuate, margins entire or with 2–4 inconspicuous teeth near apex, apex acute, abaxial surface pilose to shortly sericeous, adaxial surface usually glabrous, rarely pilose to shortly sericeous; 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, 2.1–2.6 × 1.3–2 mm, canescent; involucral lobes triangular, obscured by hairs; glands (2–)4–5, green to maroon, color often obscured by hairs, sessile and broadly attached, 0.5–0.6 × 0.5–0.6 mm, opening oblong to nearly circular, densely canescent; appendages petaloid, whitish, hoodlike, incurved and covering glands, 0.5–1 × 0.5–0.8 mm, divided into 5–12 fringed, subulate segments, densely canescent. |
Staminate flowers | 10–15. |
20–25. |
Pistillate flowers | ovary glabrous; styles 0.7–1 mm, 2-fid. |
ovary canescent; styles 0.9–1.5 mm, unbranched. |
Capsules | depressed-globose, 2.5–4 × 3.2–4.2 mm, clearly 3-lobed; cocci rounded, smooth, glabrous; columella 0.9–1.1 mm. |
oblong to ovoid, 4.4–4.9 × 3.5–4.1 mm, canescent (often with interspersed glabrescent patches); columella 3.5–3.9 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. |
mottled black and gray or light brown, oblong or slightly ovoid, dorsiventrally compressed in cross section, 2.8–4.1 × 2–2.4 mm, irregularly pitted and tuberculate; caruncle 0.4–0.8 × 0.6–1.1 mm. |
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. |
arrangement: terminal cymose branches 1, 1–2-branched; pleiochasial bracts 2–3, opposite or whorled, wholly green, similar in shape and size to distal leaves; dichasial bracts similar in shape to distal leaves or often highly reduced. |
Cyathia | peduncle 0.2–1 mm. |
peduncle 1–1.9 mm. |
Euphorbia helioscopia |
Euphorbia eriantha |
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Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting year-round in response to sufficient rainfall. |
Habitat | Roadsides, waste places. | Desert scrub on rocky slopes and along washes. |
Elevation | 0–1400 m. (0–4600 ft.) | 60–800 m. (200–2600 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; CA; NM; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, San Luis Potosí, Sonora)
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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.) |
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Source | FNA vol. 12, p. 303. | FNA vol. 12, p. 321. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | Galarhoeus helioscopius, Tithymalus helioscopius | |
Name authority | Linnaeus: Sp. Pl. 1: 459. (1753) | Bentham: Bot. Voy. Sulphur, 51. (1844) |
Web links |
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