Euphorbia floridana |
Euphorbia schizoloba |
|
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greater Florida spurge |
Mojave spurge |
|
Habit | Herbs, perennial, with slender to moderately thickened rootstock. | Herbs, perennial, with thick rootstock. |
Stems | erect, 20–65 cm. |
slender, ascending, often sinuous, many, densely branched near base, 10–50 cm, usually glabrous, usually glaucous. |
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 0–1 mm; blade broadly oblanceolate to obovate, 10–20 × 3–9 mm, base usually acute, occasionally short-attenuate, rarely obtuse, margins entire, apex usually acute, occasionally obtuse, acuminate to cuspidate, surfaces usually glabrous, usually glaucous; venation pinnate, sometimes obscure, 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. |
campanulate to broadly turbinate, 2.2–3 × 2–2.5 mm, glabrous; glands 4, irregularly semicircular to trapezoidal or elliptic-truncate, 0.8–1.5 × 1–2.2, margins strongly crenate or dentate; horns usually absent, if present then straight, 0.1–0.2 mm, generally equaling teeth on gland margin. |
Staminate flowers | 20. |
12–20. |
Pistillate flowers | 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 glabrous; styles 1–1.2 mm, 2-fid. |
Capsules | oblate-ovoid, 4.6–5.5 × 8.9–9 mm, strongly 3-lobed; columella 3.4–4.2 mm. |
oblong-ovoid, 3.5–4 × 3.8–5 mm, 3-lobed; cocci rounded, smooth, glabrous; columella 3.3–3.8 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. |
gray to whitish, oblong cylindric, 2–3 × 1.5 mm, irregularly shallowly pitted to almost smooth; caruncle conic, 0.6 × 0.6 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 (1–)3–4(–5), each 1–3 times 2-branched; pleiochasial bracts broadly ovate to subcordate, usually similar in size to, occasionally wider than, distal leaves; dichasial bracts distinct, broadly ovate to almost reniform, base obtuse, margins entire, apex obtuse, acuminate to cuspidate; axillary cymose branches 0–2(–4). |
Cyathia | peduncle (except for that of 1st cyathium at base of pleiochasia) 2–5 mm (not exceeding dichasial bracts). |
peduncle 0.3–1 mm. |
Euphorbia floridana |
Euphorbia schizoloba |
|
Phenology | Flowering and fruiting spring–fall. | Flowering and fruiting spring–summer. |
Habitat | Xeric pine-oak sandhills, pine scrub, sandy soils. | Desert mountains and canyon slopes, rocky and gravelly soils. |
Elevation | 20–80 m. (100–300 ft.) | 500–1800 m. (1600–5900 ft.) |
Distribution |
AL; FL; GA
|
AZ; CA; NV
|
Discussion | Euphorbia schizoloba is a desert perennial that occurs on bluffs and ledges in the Mojave and Sonoran Deserts. Sparsely pubescent plants of E. schizoloba are known from Arizona and are best represented by several collections from the Mazatzal and Sierra Ancha mountains in Gila County from between 1000 to 1800 meters. George Engelmann published two names for this species almost simultaneously in 1861 (E. schizoloba and E. incisa). Although the authors have not been able to determine which publication has priority, Engelmann himself cited E. incisa as a synonym of E. schizoloba (in W. H. Brewer et al. 1876–1880, vol. 2), as did J. B. S. Norton (1899). Also, the type specimen at MO was annotated by Engelmann as E. schizoloba, and there is no mention of the name E. incisa on the sheet. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 12, p. 314. | FNA vol. 12, p. 309. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Nummulariopsis | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Galarhoeus floridanus | E. incisa, Tithymalus incisus, T. schizolobus |
Name authority | Chapman: Fl. South. U.S., 401. (1860) | Engelmann: Proc. Amer. Acad. Arts 5: 173. (1861) |
Web links |