Euphorbia lurida |
Euphorbia conferta |
|
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woodland spurge |
Everglade key sandmat |
|
Habit | Herbs, perennial, with thick rootstock. | Herbs, annual, with taproot. |
Stems | erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent. |
prostrate, ascending, to erect, 10–45 cm, pilose. |
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, subulate, 1–2 mm, pilose; petiole 0.9–1.5 mm, pilose; blade oblanceolate to elliptic, 3–10 × 1–4 mm, base asymmetric, obtuse to hemicordate, margins coarsely serrate, sometimes revolute, apex rounded to acute, abaxial surface sparsely hispidulous to strigillose (densely so on young leaves), adaxial surface glabrous; 3-veined from base but only midvein conspicuous. |
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, 1.1–1.4 × 0.5–0.7 mm, pilose; glands 4, red, narrowly reniform, 0.1 × 0.2–0.4 mm; appendages pink to red, larger 2 petal-like, smaller 2 elliptic, 0.4–1 × 0.3–0.5 mm, distal margin erose. |
Staminate flowers | 10–20. |
5–8. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid. |
ovary pilose; styles 0.4–0.8 mm, 2-fid at apex. |
Capsules | ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 mm. |
conic or truncate-ovoid, 1–1.2 mm diam., pilose; columella 0.9–1.1 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. |
orange-brown, glaucous, oblong, 4-angled in cross section, 0.7–0.8 × 0.4–0.5 mm, slightly rugose and with 3–4 transverse 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. |
solitary at distal nodes (appearing clustered at points of new growth); peduncle 0.4–0.6 mm. |
Euphorbia lurida |
Euphorbia conferta |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting year-round. |
Habitat | Open pine-oak forests, dry slopes and canyons. | Sandy, disturbed, wet areas, often roadsides. |
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 conferta is known only from Broward, Miami-Dade, and Monroe counties in southern Florida. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 305. | FNA vol. 12, p. 264. |
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 conferta |
Name authority | Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861) | (Small) B. E. Smith: J. Elisha Mitchell Sci. Soc. 62: 82. (1946) |
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