Euphorbia agraria |
Euphorbia cyathophora |
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urban spurge |
fire on the mountain, painted leaf, painted poinsettia |
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Habit | Herbs, perennial, with slender, spreading rootstock. | Herbs, annual, with spreading taproots. |
Stems | erect or ascending, unbranched or branched, 30–90 cm, glabrous. |
erect or ascending, 20–100 cm, glabrous, sparsely pilose, or puberulent; branches ± straight. |
Leaves | petiole absent; blade oblong-elliptic, 20–65 × 9–20 mm, base truncate to auriculate, margins entire, apex obtuse to rounded, surfaces glabrous; venation conspicuously pinnate, midvein prominent. |
usually alternate, occasionally opposite proximally; petiole 2–20 mm, glabrous or pilose, or often hispid abaxially near blade junction; blade linear, lanceolate, elliptic, or wider leaves pandurate and unequally 4-lobed, occasionally polymorphic on single plants, 15–250 × 4–40 mm, base acute to cuneate, margins subulately glandular-serrulate distally, or sparsely glandular and subentire, hirtellous to glabrate, flat to revolute, apex acute to cuneate, abaxial surface sparsely pilose or glabrate, adaxial surface glabrous or sparsely puberulent; venation pinnate, midvein prominent. |
Involucre | campanulate, 2.2–3 × 1.8–2 mm, glabrous; glands 4, crescent-shaped; 0.6–1 × 1–2 mm; horns slightly divergent to convergent, 0.1–0.2 mm. |
campanulate, occasionally broadly so, 1.8–2.8 × 2.2–2.8 mm, glabrous; involucral lobes triangularly 3–5 lobed; gland 1, yellow-green, sessile to substipitate and narrowly to broadly attached, 1–1.4 × 0.9–1.6 mm, opening oblong (flattened without pressing), without annular rim, glabrous; appendages absent. |
Staminate flowers | 15–20. |
7–20. |
Pistillate flowers | ovary glabrous; styles 1.2–2 mm, 2-fid. |
ovary glabrous; styles 1.6 mm, 2-fid nearly entire length. |
Capsules | globose, 2–2.8 × 2.2–2.7 mm, 3-lobed; cocci rounded, smooth except finely granulate toward abaxial line, glabrous; columella 2.1–2.7 mm. |
green, depressed-globose to ellipsoid, 2.8–3.2 × 4–4.5 mm, 3-lobed, glabrous; columella 2–2.7 mm. |
Seeds | gray or whitish, ovoid-oblong, 2–2.1 × 1.2–1.3 mm, smooth; caruncle ± rounded and flattened, 0.8 × 0.6 mm. |
black to ashy gray or light brown, cylindric to ovoid, rounded in cross section, 2.3–3.1 × 1.9–2.5 mm, uniformly tuberculate or tubercles arranged in median, transverse ridge in cylindric seeds; caruncle absent. |
Cyathial | arrangement: terminal pleiochasial branches 8–15, 1–2 times 2-branched; pleiochasial bracts similar in shape but shorter and narrower than distal leaves; dichasial bracts distinct, rhombic to reniform, base obtuse, margins entire, apex obtuse, mucronate; axillary cymose branches 12–23. |
arrangement: terminal pleiochasial branches (1–)3, 1–2-branched; pleiochasial bracts 2–3(–4), often as tight, involucrate whorl, usually green with white, pink, or red at base, occasionally distal bracts wholly white, pink, or red, rarely all bracts wholly green, similar in shape and size to distal leaves; dichasial bracts often colored, similar in shape and size to distal stem leaves or highly reduced. |
Cyathia | peduncle 0–2 mm. |
peduncle 1.6–2.8 mm. |
2n | = 28, 56. |
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Euphorbia agraria |
Euphorbia cyathophora |
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Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting late spring–fall. |
Habitat | Grasslands, roadside banks, pastures. | Bottomland forests, stream and river banks, bases of bluffs, fallow fields, roadsides, open disturbed areas. |
Elevation | 200–1600 m. (700–5200 ft.) | 0–1800 m. (0–5900 ft.) |
Distribution |
KS; MT; NE; NY; PA; WA; WY; AB; SK; Europe [Introduced in North America]
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AL; AR; CA; FL; GA; IA; IL; IN; KS; KY; LA; MD; MN; MO; MS; NC; NE; NM; OH; OK; SC; SD; TN; TX; UT; VA; WI; Mexico; Central America; South America; West Indies [Introduced in Eurasia, Africa, Indian Ocean Islands, Pacific Islands, Australia]
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Discussion | Euphorbia cyathophora is native to the midwestern and southeastern United States, Mexico, the West Indies, and northern South America. Leaf shape can be polymorphic on individuals of this species, but not to the extent as in E. heterophylla. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 298. | FNA vol. 12, p. 319. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | Tithymalus agrarius | Poinsettia cyathophora |
Name authority | M. Bieberstein: Fl. Taur.-Caucas. 1: 375. (1808) | Murray: Commentat. Soc. Regiae Sci. Gott. 7: 81, plate 1. (1786) |
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