Euphorbia lurida |
Euphorbia pinetorum |
|
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woodland spurge |
pineland spurge |
|
Habit | Herbs, perennial, with thick rootstock. | Herbs, perennial, with thickened, woody taproot. |
Stems | erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent. |
erect, 30–100 cm, glabrous; branches ± straight. |
Leaves | petiole 0–1 mm; blade oblanceolate to obovate, 8–20 mm × 3–7 mm, base truncate or cuneate, margins entire, apex obtuse to rounded, minutely mucronate, surfaces puberulent or glabrous; venation inconspicuous, only midvein prominent. |
usually alternate, occasionally opposite proximally; petiole 0–1.5 mm, glabrous; blade narrowly lanceolate to linear, base long-attenuate, 30–120 × 2.5–5 mm, margins usually entire, occasionally with few inconspicuous teeth, revolute, apex narrowly acute, surfaces glabrous; venation obscurely pinnate, midvein prominent. |
Involucre | cupulate, 2–2.2 × 1.3–1.8 mm, glabrous; glands 4, oblong to broadly ovate, usually truncate, 0.5–0.8 × 1–1.6 mm, margins irregularly crenate to strongly dentate; horns absent or usually divergent or straight, 0.1–0.3 mm, usually slightly longer than, occasionally equaling, teeth on gland margin. |
campanulate, 1.5–1.9 × 1.4–1.7 mm, glabrous; involucral lobes divided into broad, triangular segments; glands 3(–5), red to purple, sessile and broadly attached, 0.8–1.1 × 1.2–1.6 mm, opening oblong (flattened without pressing), without annular rim, glabrous; appendages absent. |
Staminate flowers | 10–20. |
8–12. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid. |
ovary glabrous; styles 1.5 mm, 2-fid nearly entire length. |
Capsules | ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 mm. |
purpurescent, depressed-globose, 2.8–3.2 × 3.6–4 mm, 3-lobed, glabrous; columella 2.6–2.9 mm. |
Seeds | gray to dark gray, truncate-oblong to truncate-ovoid, 2.8–3 × 1.7–2 mm, irregularly pitted; caruncle conic, 0.6 × 0.7 mm. |
dark brown, cylindric-ovoid to ovoid, rounded in cross section, 2.1–2.4 × 2 mm, uniformly low-tuberculate, tubercles in median, transverse ridge; caruncle absent. |
Cyathial | arrangement: terminal pleiochasial branches 3–5, each 1–4 times 2-branched; pleiochasial bracts ovate to broadly ovate or oblanceolate, wider than distal leaves; dichasial bracts distinct, rounded, oblanceolate, or subreniform, base cuneate or obtuse, margins entire, apex obtuse, slightly mucronate; axillary cymose branches 0–4. |
arrangement: terminal monochasial or dichasial branches 1–2, unbranched; pleiochasial bracts 2–3, often whorled, wholly purpurescent green or pink at base, similar in shape and size to distal leaves or slightly narrower; dichasial bracts highly reduced. |
Cyathia | peduncle 0.3–0.9 mm. |
peduncle 1.5–3 mm. |
Euphorbia lurida |
Euphorbia pinetorum |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round. |
Habitat | Open pine-oak forests, dry slopes and canyons. | Sandy soils in pinelands. |
Elevation | 1300–2800 m. (4300–9200 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AZ; CA; NM; NV; UT; Mexico (Baja California)
|
FL |
Discussion | Euphorbia lurida has been treated as a complex of several taxa in the past, but only a single, broadly-defined species is recognized here. This species is variable in both the pubescence and shape of the bracts subtending the cyathia and also in the degree of crenation of the gland margin. In the northern part of its range, E. lurida appears to intergrade with E. brachycera, and it can be difficult to distinguish these two species in northern Arizona and New Mexico. A report of the species from Sonora, Mexico, based on a single immature collection (V. W. Steinmann and R. S. Felger 1997) has not been verified. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia pinetorum has a restricted distribution in southern peninsular Florida, primarily in Miami-Dade and Monroe counties. The species is very similar to narrow-leaved forms of the closely related E. cyathophora but differs in its perennial habit, consistently unlobed leaves, and purpurescent involucral glands and cyathia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 323. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Poinsettia |
Sibling taxa | ||
Synonyms | E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens | Poinsettia pinetorum |
Name authority | Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861) | (Small) G. L. Webster: J. Arnold Arbor. 48: 403. (1967) |
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