Euphorbia bicolor |
Euphorbia misera |
|
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snow-on-the-prairie |
cliff spurge |
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Habit | Herbs, annual, with taproot. | Shrubs, soft wooded, with woody rootstock. |
Stems | erect, unbranched or branched, 40–100 cm, pilose. |
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 | alternate; stipules 0.3–0.4 mm; petiole 0.3–1 mm, pilose; blade narrowly elliptic to lanceolate, 37–54 × 7–17 mm, base cuneate to slightly rounded, margins entire, apex aristate or acute, surfaces pilose; venation obscure, only midvein conspicuous. |
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 | campanulate, 2.7–3.5 × 2.2–3 mm, densely pilose; glands 4–5, green to pale greenish yellow, reniform, 0.6–0.7 × 1.4–1.6 mm; appendages white, obdeltate to orbiculate, 1.4–2.5 × 1.7–3 mm, dentate to erose. |
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 | 30–70. |
40–50. |
Pistillate flowers | ovary pilose; styles 0.7–1.2 mm, 2-fid 1/2 length. |
ovary glabrous or puberulent; styles 1.6–2.7 mm, 2-fid at apex. |
Capsules | depressed-ovoid, 3.5–7.5 × 6–8.7 mm, densely pilose; columella 4.5–5.5 mm. |
oblate, 4.6–5.1 × 6.1–6.7 mm, usually glabrous or glabrescent, occasionally puberulent; columella 2.8–3.6 mm. |
Seeds | tan to brown, ovoid, 4.3–4.5 × 3.7–3.9 mm, alveolate; caruncle absent. |
grayish, subglobose to ovoid, rounded in cross section, 2.7–3.3 × 2.5–2.8 mm, foveolate; caruncle absent. |
Cyathia | in terminal pleiochasia dichasial and pleiochasial bracts linear to narrowly oblanceolate, with conspicuous white margins; peduncle 1.2–3 mm, densely pilose. |
usually solitary on short shoots, peduncle 1.8–10.5 mm, puberulent-tomentose. |
Euphorbia bicolor |
Euphorbia misera |
|
Phenology | Flowering and fruiting summer–fall. | Flowering and fruiting year-round (but most prolific after winter rains). |
Habitat | Prairies, blackland (calcareous) prairies, pastures and clearings in former blackland prairie areas, roadside clearings. | Rocky soils, sometimes in crevices of vertical cliff faces, coastal scrub, maritime desert scrub, arid desert scrub. |
Elevation | 100–200 m. (300–700 ft.) | 0–400 m. (0–1300 ft.) |
Distribution |
AR; LA; OK; TX
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CA; Mexico (Baja California, Baja California Sur, Sonora)
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Discussion | Euphorbia bicolor is similar in appearance to E. marginata but can be distinguished by its linear to narrowly oblanceolate bracts and the presence of hairs on all parts of the plant. (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. 243. | FNA vol. 12, p. 249. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Name authority | Engelmann & A. Gray: Boston J. Nat. Hist. 5: 233. (1845) | Bentham: Bot. Voy. Sulphur, 51. (1844) |
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