Euphorbia lurida |
Euphorbia lasiocarpa |
|
---|---|---|
woodland spurge |
roadside sandmat |
|
Habit | Herbs, perennial, with thick rootstock. | Herbs, annual or perennial, often robust, with slender to moderately thickened taproot. |
Stems | erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent. |
erect to ascending, 30–100 cm, pilose to tomentose. |
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. |
opposite; stipules distinct when young, connate into deltate scale when older, erose to laciniate, with dark glands at margin or base, 0.5–1.3 mm, pilose; petiole 0.5–2 mm, glabrescent or pilose; blade ovate or oblong, sometimes slightly falcate, 8–46 × 3–21 mm, base asymmetric, obtuse to hemicordate, margins serrulate, apex obtuse or acute, surfaces often with red spot in center, pilose to sericeous; palmately 3–5(–7)-veined from base. |
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. |
obconic, 0.9–1.3 × 0.8–1.2 mm, pilose to sericeous; glands 4, yellow or pink, circular or oblong, 0.1–0.3 mm diam.; appendages white or pink, oblong, flabellate, or suborbiculate, 0.1–0.6 × 0.2–1 mm, entire or crenate. |
Staminate flowers | 10–20. |
15–25. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid. |
ovary densely pilose to sericeous with yellowish hairs; styles 0.6–0.9 mm, 2-fid 1/2 length, filiform. |
Capsules | ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 mm. |
subglobose to broadly ovoid, 1.7–2 mm diam., pilose to sericeous with yellowish hairs; columella 1.5–1.7 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 reddish brown to almost black, plumply ovoid, 4-angled in cross section, 1.2–1.3 × 0.7–0.8 mm, with 2 inconspicuous rows of 3–5 shallow depressions separated by low ridges. |
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. |
|
Cyathia | peduncle 0.3–0.9 mm. |
in dense, usually terminal, capitate glomerules, with reduced, bractlike leaves subtending cyathia; peduncle 0.8–2.3 mm. |
Euphorbia lurida |
Euphorbia lasiocarpa |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round. |
Habitat | Open pine-oak forests, dry slopes and canyons. | Open disturbed areas, mostly along roadsides and railroad tracks. |
Elevation | 1300–2800 m. (4300–9200 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
AZ; CA; NM; NV; UT; Mexico (Baja California)
|
FL; Mexico; Central America; South America; West Indies [Introduced in North America] |
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 lasiocarpa is similar to E. hypericifolia but is much more hairy on its stems and leaves. Euphorbia lasiocarpa is widespread throughout tropical America, but its precise native range in the New World is not clear. In the flora area, E. lasiocarpa is found in southern Florida, where it is likely introduced. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 275. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens | Chamaesyce lasiocarpa |
Name authority | Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861) | Klotzsch: Nov. Actorum Acad. Caes. Leop.-Carol. Nat. Cur. 19(suppl. 1): 414. (1843) |
Web links |