Euphorbia floridana |
Euphorbia brachycera |
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greater Florida spurge |
horned spurge, shorthorn spurge |
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Habit | Herbs, perennial, with slender to moderately thickened rootstock. | Herbs, perennial, with thick rootstock. |
Stems | erect, 20–65 cm. |
erect or ascending, branched, 10–60 cm, usually glabrous, sometimes puberulent. |
Leaves | 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. |
petiole 0–0.5 mm; blade oblong-elliptic, lanceolate, or oblanceolate to broadly ovate, 5–25 × 2–7 mm, base truncate, rounded, acute, or attenuate, margins entire, apex acute or obtuse, sometimes mucronate, surfaces usually glabrous, sometimes puberulent; venation inconspicuous, only midvein prominent. |
Involucre | 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. |
turbinate, campanulate or cupulate, 1.5–2.6 × 1.4–1.7 mm, usually glabrous, sometimes puberulent; glands 4, crescent-shaped to triangular-ovate, 0.5–0.8 × 0.7–1.7 mm, margins usually entire, occasionally slightly crenate to dentate; horns divergent, 0.2–0.4 mm, longer than teeth on gland margin. |
Staminate flowers | 20. |
10–15. |
Pistillate flower(s) | 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. |
ovary, usually glabrous, sometimes puberulent; styles 0.5–0.9 mm, 2-fid. |
Capsules | oblate-ovoid, 4.6–5.5 × 8.9–9 mm, strongly 3-lobed; columella 3.4–4.2 mm. |
depressed-ovoid, 2.8–4 × 3.5–4.5 mm, 3-lobed; cocci rounded, smooth, usually glabrous, sometimes sparsely puberulent; columella 2.4–3.3 mm. |
Seeds | 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. |
light gray, cylindric ovoid-oblong, 2–2.8(–3) × 1.4–2.2 mm, irregularly shallowly pitted; caruncle sessile to shortly stipitate, conic, 0.4–0.5 × 0.8–1.1 mm. |
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). |
arrangement: terminal pleiochasial branches 3–5(–8), 1–4+ times 2-branched; pleiochasial bracts lanceolate or ovate to broadly ovate, wider than distal leaves; dichasial bracts distinct, broadly ovate or rhombic to triangular-ovate, base obtuse, margins entire or slightly crenate, apex obtuse, mucronate; axillary cymose branches 0–8. |
Cyathia | peduncle (except for that of 1st cyathium at base of pleiochasia) 2–5 mm (not exceeding dichasial bracts). |
peduncle 0.4–1 mm. |
2n | = 28. |
|
Euphorbia floridana |
Euphorbia brachycera |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Xeric pine-oak sandhills, pine scrub, sandy soils. | Montane areas, canyons, rock crevices, sandy or gravelly slopes, pine-oak woodlands, ponderosa pine and mixed coniferous forests. |
Elevation | 20–80 m. (100–300 ft.) | 1200–3200 m. (3900–10500 ft.) |
Distribution |
AL; FL; GA
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AZ; CO; ID; MT; ND; NE; NM; SD; TX; UT; WY; Mexico (Chihuahua, Coahuila, Sonora)
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Discussion | Euphorbia brachycera is morphologically extremely variable, and plants from the northern part of the species range have sometimes been distinguished as E. robusta. Euphorbia brachycera is most closely related to the other native, perennial species of subg. Esula in western North America, namely E. chamaesula, E. lurida, E. schizoloba, and E. yaquiana. The name E. montana Engelmann, which has sometimes been applied to E. brachycera, is illegitimate because it is a later homonym of E. montana Rafinesque. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 314. | FNA vol. 12, p. 300. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Nummulariopsis | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Galarhoeus floridanus | E. brachycera var. robusta, E. montana var. robusta, E. odontadenia, E. robusta, Tithymalus brachycerus, T. robustus |
Name authority | Chapman: Fl. South. U.S., 401. (1860) | Engelmann: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 192. (1859) |
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