Euphorbia bilobata |
Euphorbia floridana |
|
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black-seed spurge |
greater Florida spurge |
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Habit | Herbs, annual, with slender taproot. | Herbs, perennial, with slender to moderately thickened rootstock. |
Stems | erect, branched, 10–35 cm, glabrous or strigillose (especially when young and around nodes). |
erect, 20–65 cm. |
Leaves | opposite proximally, alternate distally; stipules 0.1–0.2 mm; petiole 1–4(–6) mm, glabrous, sericeous or strigillose; blade linear to narrowly elliptic, 8–52 × 2–7 mm, base attenuate, margins entire, ciliate-strigose, apex acute, abaxial surface sparsely strigillose to sericeous, adaxial surface usually glabrous; venation obscure, only midvein conspicuous. |
petiole absent; blade linear to linear-elliptic or linear-lanceolate, 30–105 × 2–4(–7) mm, chartaceous, base attenuate, rounded, or nearly truncate, apex acute; only midvein evident. |
Involucre | obconic, 0.9–1.5 × 0.9–1.3 mm, strigillose to pilose; glands 5, yellow or pink, U-shaped, 0.2–0.3 × 0.4–0.5 mm; appendages greenish, white, or pink, forming narrow rim around gland, or ovate, oblong, or obovate and usually 2-fid, rarely rudimentary, 0.2–1.4 × 0.2–0.6 mm, entire. |
campanulate or obconic, 1.6–3.3 × 1.8–3.1 mm, lobes ovate, 0.5–0.7 mm, ciliate, exceeded by glands; glands yellow-green, oblong to trapezoidal, 0.5–0.8 × 0.8–1.2 mm, distal margins deeply erose. |
Staminate flowers | 20–25. |
20. |
Pistillate flowers | ovary glabrous, puberulent, strigillose, or pilose; styles 0.5–0.8 mm, 2-fid 1/3–1/2 length. |
gynophore exserted 2.9–5.3 mm, calyxlike lobes triangular, 0.3–0.7 mm; styles connate 1/3–1/4 length, 1.1–1.7 mm. |
Capsules | oblate, 1.5–2.6 × 2.1–3.3 mm, glabrous or puberulent, strigillose, or pilose; columella 1.2–2.1 mm. |
oblate-ovoid, 4.6–5.5 × 8.9–9 mm, strongly 3-lobed; columella 3.4–4.2 mm. |
Seeds | brown to grayish black, narrowly ovoid, 3- or 4-angled in cross section, sometimes obscurely so, 1.3–1.9 × 1–1.4 mm, tuberculate, often with shallow depressions; caruncle absent. |
brown to blackish, depressed-globose, circular in cross section, 2.8–3 × 3.2–3.6 mm, smooth, base flattened, with punctiform depressions, apex flattened. |
Cyathia | solitary at distal nodes or in weakly defined cymes or dichasia, dichasial bracts and distal stem leaves wholly green; peduncle 0.5–3.6 mm, strigillose. |
peduncle (except for that of 1st cyathium at base of pleiochasia) 2–5 mm (not exceeding dichasial bracts). |
Cyathial | arrangement: terminal pleiochasial branches 3–5, 3–16 cm, 3–5(–7) times 2-branched; pleiochasial bracts linear-lanceolate or narrowly ovate, 19–55 × 4–12 mm, margins entire, apex acute or acuminate; dichasial bracts usually ovate, lanceolate, or oblong, rarely deltate, 8–21 × 4–14 mm, margins entire, apex acute, acuminate, or rounded with mucronate tip; axillary cymose branches 1–3(–6). |
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2n | = 32. |
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Euphorbia bilobata |
Euphorbia floridana |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–fall. |
Habitat | Sandy and rocky soils on slopes and canyon bottoms in pine-juniper woodlands, oak woodlands, grasslands. | Xeric pine-oak sandhills, pine scrub, sandy soils. |
Elevation | 1400–2600 m. (4600–8500 ft.) | 20–80 m. (100–300 ft.) |
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Durango, Sonora)
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AL; FL; GA
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Discussion | In Texas, Euphorbia bilobata is known only from Jeff Davis County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 12, p. 243. | FNA vol. 12, p. 314. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Nummulariopsis |
Sibling taxa | ||
Synonyms | Galarhoeus floridanus | |
Name authority | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 190. (1859) | Chapman: Fl. South. U.S., 401. (1860) |
Web links |