Euphorbia cyathophora |
Euphorbia serrula |
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fire on the mountain, painted leaf, painted poinsettia |
sawtooth sandmat |
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Habit | Herbs, annual, with spreading taproots. | Herbs, annual, with slender taproot. |
Stems | erect or ascending, 20–100 cm, glabrous, sparsely pilose, or puberulent; branches ± straight. |
prostrate or ascending, 5–20 cm, usually pilose to villous, rarely glabrate. |
Leaves | 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. |
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 | 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. |
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 | 7–20. |
7–15. |
Pistillate flowers | ovary glabrous; styles 1.6 mm, 2-fid nearly entire length. |
ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 length. |
Capsules | green, depressed-globose to ellipsoid, 2.8–3.2 × 4–4.5 mm, 3-lobed, glabrous; columella 2–2.7 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 | 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. |
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 (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. |
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Cyathia | peduncle 1.6–2.8 mm. |
solitary at distal nodes; peduncle 0.4–1.8(–2.3) mm. |
2n | = 28, 56. |
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Euphorbia cyathophora |
Euphorbia serrula |
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Phenology | Flowering and fruiting late spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Bottomland forests, stream and river banks, bases of bluffs, fallow fields, roadsides, open disturbed areas. | Desert scrub, with creosote bush, grasslands with mesquite and yucca, rarely in ponderosa pine woodlands, often sandy substrates. |
Elevation | 0–1800 m. (0–5900 ft.) | 300–1900 m. (1000–6200 ft.) |
Distribution |
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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AZ; NM; TX; Mexico
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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.) |
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. 319. | FNA vol. 12, p. 288. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Poinsettia cyathophora | Chamaesyce serrula |
Name authority | Murray: Commentat. Soc. Regiae Sci. Gott. 7: 81, plate 1. (1786) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 188. (1859) |
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