Euphorbia heterophylla |
Euphorbia misera |
|
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Mexican fireplant, painted euphorbia |
cliff spurge |
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Habit | Herbs, annual, with taproot. | Shrubs, soft wooded, with woody rootstock. |
Stems | erect-ascending, 20–100 cm, sparsely pilose to villous; branches ± straight. |
erect to ascending, often gnarled and scraggly, branched, with conspicuous knobby short shoots, 70–150 cm, puberulent-tomentose, bark grayish red to light gray. |
Leaves | usually alternate, occasionally opposite proximally; petiole 10–50 mm, pilose; blade narrowly lanceolate to elliptic or broadly obovate (then usually pandurate and 4-lobed), often polymorphic on single plants, 30–200 × 20–140 mm, base acute, margins sparsely glandular-serrulate, hirtellous, flat, apex acute to obtuse, abaxial surface sparsely appressed-pilose, adaxial surface sparsely pilosulous to glabrate; venation pinnate, midvein prominent. |
alternate, well spaced on long shoots or fasciculate on short shoots; stipules 0.6–1.1 mm; petiole 4–12(–19) mm, slender, puberulent to shortly pilose; blade oblong, ovate, orbiculate, elliptic, or obovate, 6–24 × 5–21 mm, base rounded to cuneate, margins entire, apex acute to obtuse, surfaces puberulent-tomentose; venation conspicuous. |
Involucre | usually campanulate, occasionally nearly hemispheric, 1.5–1.9 × 1.2–1.8 mm, glabrous; involucral lobes divided into several linear, smooth lobes; gland 1, yellow-green, stipitate, clavate, 1–1.4 × 1–1.2 mm, opening circular (occasionally flattened from pressing), with annular rim, glabrous; appendages absent. |
campanulate, 1.4–3.8 × 2.1–4.4 mm, puberulent-tomentose; glands 5, yellow to reddish, oblong to reniform, 0.7–1.3 × 1.1–2.6 mm; appendages green-yellow to yellowish or whitish, oblong to transversely oblong, 0.6–1.9 × 1.3–3.8 mm, crenulate to erose. |
Staminate flowers | 8–15. |
40–50. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.8–1.3 mm, 2-fid 1/2 to nearly entire length. |
ovary glabrous or puberulent; styles 1.6–2.7 mm, 2-fid at apex. |
Capsules | broadly ovoid, 2.8–3.8 × 4–5.3 mm, 3-lobed, usually glabrous, rarely sparsely puberulent; columella 2.1–2.8 mm. |
oblate, 4.6–5.1 × 6.1–6.7 mm, usually glabrous or glabrescent, occasionally puberulent; columella 2.8–3.6 mm. |
Seeds | brown-gray to ashy gray, broadly deltoid, 2.4–2.8 × 1.9–2.4 mm, angular in cross section, dorsal face strongly acute-carinate, tuberculate, with broad rounded tubercles in 2 rows; caruncle 0.1 mm. |
grayish, subglobose to ovoid, rounded in cross section, 2.7–3.3 × 2.5–2.8 mm, foveolate; caruncle absent. |
Cyathial | arrangement: terminal dichasial branches usually 2, occasionally reduced to congested cyme, 1–2-branched (often congested and difficult to discern); pleiochasial bracts 2–4, often whorled, wholly green or paler green at base, similar in shape and size to distal leaves; dichasial bracts highly reduced, rarely absent in highly congested clusters. |
|
Cyathia | peduncle 0.9–1.5 mm. |
usually solitary on short shoots, peduncle 1.8–10.5 mm, puberulent-tomentose. |
2n | = 28. |
|
Euphorbia heterophylla |
Euphorbia misera |
|
Phenology | Flowering and fruiting nearly year-round. | Flowering and fruiting year-round (but most prolific after winter rains). |
Habitat | Disturbed areas, roadsides. | Rocky soils, sometimes in crevices of vertical cliff faces, coastal scrub, maritime desert scrub, arid desert scrub. |
Elevation | 0–500 m. (0–1600 ft.) | 0–400 m. (0–1300 ft.) |
Distribution |
Mexico; Central America; South America [Introduced, Ala., Ariz., Calif., Fla., Ga., La., Miss., N.Mex., Tex.; introduced also in Eurasia, Africa]
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CA; Mexico (Baja California, Baja California Sur, Sonora)
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Discussion | Euphorbia heterophylla occurs from the southern United States, where it is likely naturalized, south through Mexico and Central America to South America. Because of its weediness, the precise native range in tropical and subtropical parts of the New World is not well understood. It has become widely established also in warm areas of the Old World. Leaf shape in this species is highly polymorphic within both populations and individuals. Euphorbia heterophylla can appear superficially similar to E. cyathophora but differs in its stipitate, circular involucral glands and its floral bracts that are at most very pale at the base (never colored as is typical in E. cyathophora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia misera is relatively infrequent within the flora area, known primarily from coastal southern California and the Channel Islands (although a relictual inland population occurs in the Little San Bernardino Mountains). The species has been considered worthy of conservation, but appears to be under little threat, especially in Mexico where it is frequent and often locally abundant. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 323. | FNA vol. 12, p. 249. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Poinsettia | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Synonyms | E. geniculata, Poinsettia geniculata, P. heterophylla | |
Name authority | Linnaeus: Sp. Pl. 1: 453. (1753) | Bentham: Bot. Voy. Sulphur, 51. (1844) |
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