Euphorbia albomarginata |
Euphorbia purpurea |
|
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rattlesnake sandmat, rattlesnake weed, white-margin sandmat or sandwort, whitemargin sandmat |
Darlington's glade spurge, glade or Darlington's glade spurge |
|
Habit | Herbs, perennial, with moderately to strongly thickened rootstock. | Herbs, perennial, with thick rootstock. |
Stems | prostrate, occasionally mat-forming, frequently rooting at nodes, 10–80 cm, glabrous. |
erect, unbranched, 70–100(–130) cm, glabrous. |
Leaves | opposite; stipules connate into conspicuous, deltate or ovate scale, white, 0.4–1(–2) mm, glabrous; petiole less than 1 mm, glabrous; blade ovate, oblong or orbiculate, 3–8(–15) × 3–7 mm, base strongly asymmetric, obtuse to hemicordate, margins whitish, entire, apex obtuse, rarely mucronulate, surfaces often with red blotch in center, glabrous; 3-veined from base but usually only midvein conspicuous. |
petiole 0–2 mm; blade lance-oblong to oblanceolate-oblong, 50–100 × 13–30 mm, base attenuate to cuneate, margins entire, apex usually acute, sometimes obtuse to rounded, minutely apiculate, abaxial surface glabrate to sparsely pilose, adaxial surface glabrous; venation pinnate, midvein prominent. |
Involucre | campanulate, 0.8–1.1 × 0.9–2 mm, glabrous; glands 4, greenish yellow to red, usually oblong to reniform, rarely subcircular, 0.2–0.5 × (0.2–)0.3–0.8 mm; appendages white to pink, flabellate to oblong, 0.3–1 × 0.6–1.3 mm, distal margin entire or crenulate to erose. |
narrowly campanulate, 2.1–3 × 3–4.2 mm, glabrous; glands 5, elliptic to slightly reniform, 1–1.2 × 1.5–2.1 mm; horns absent. |
Staminate flowers | 15–30. |
10–15. |
Pistillate flowers | ovary glabrous; styles 0.3–0.7 mm, 2-fid nearly entire length. |
ovary glabrous; styles 3–3.5 mm, 2-fid. |
Capsules | broadly ovoid, 1.1–2.3 × 1.2–2 mm, glabrous; columella 1.1–1.6 mm. |
globose, 4.5–5.2 × 6–6.8 mm, 3-lobed; cocci rounded, verrucose, sometimes minutely so, glabrous; columella 4–4.8 mm. |
Seeds | white to gray or brownish red, oblong-ovoid, 4-angled in cross section, 1–1.7 × 0.5–0.8 mm, smooth. |
mottled silver-brown, ovoid-globose, 3–4 × 2.5–3.5 mm, smooth; caruncle subconic, reniform, 0.8–1.1 × 1.4–1.6 mm. |
Cyathia | solitary at distal nodes; peduncle 1–4 mm. |
peduncle 0–1 mm. |
Cyathial | arrangement: terminal pleiochasial branches 3–6, each unbranched or 1–2 times 2-branched, occasionally appearing pendent; pleiochasial bracts lance-ovate, shorter than distal leaves; dichasial bracts distinct, cordate-deltate to reniform, base subcordate, margins entire, apex rounded; axillary cymose branches 0–10. |
|
Euphorbia albomarginata |
Euphorbia purpurea |
|
Phenology | Flowering and fruiting year-round. | Flowering and fruiting spring–fall. |
Habitat | Disturbed areas in desert scrub, grasslands, mesquite woodlands, chaparral. | Dry to moist forests and slopes, rock outcrops, swamps or seeps, especially over calcareous rocks. |
Elevation | 0–2300 m. (0–7500 ft.) | 50–1100 m. (200–3600 ft.) |
Distribution |
AZ; CA; CO; NM; NV; OK; TX; UT; Mexico [Introduced in Pacific Islands (Hawaii)]
|
DE; MD; NC; NJ; OH; PA; VA; WV |
Discussion | Euphorbia albomarginata is native to northern and central Mexico and the southwestern and south-central United States. The species occurs in a variety of habitats in western North America and in some areas is quite weedy. It has been recorded as a waif in Louisiana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia purpurea is primarily an eastern Appalachian forest species, but it also occurs in Adams, Highland, and Pike counties in southern Ohio. It is listed as endangered by Maryland, New Jersey, Ohio, and Pennsylvania, and is in the Center for Plant Conservation's National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 259. | FNA vol. 12, p. 308. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | Chamaesyce albomarginata | Agaloma purpurea, Galarhoeus darlingtonii |
Name authority | Torrey & A. Gray: in War Department [U.S.], Pacif. Railr. Rep. 2(4): 174. (1857) | (Rafinesque) Fernald: Rhodora 34: 25. (1932) |
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