Euphorbia lurida |
Euphorbia purpurea |
|
---|---|---|
woodland spurge |
Darlington's glade spurge, glade or Darlington's glade spurge |
|
Habit | Herbs, perennial, with thick rootstock. | Herbs, perennial, with thick rootstock. |
Stems | erect or ascending, unbranched, sometimes sinuous, 5–30 cm, glabrous or sparsely to densely puberulent. |
erect, unbranched, 70–100(–130) cm, glabrous. |
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. |
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 | 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. |
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 | 10–20. |
10–15. |
Pistillate flowers | ovary glabrous or puberulent; styles 0.7–1 mm, 2-fid. |
ovary glabrous; styles 3–3.5 mm, 2-fid. |
Capsules | ovoid, 3.5–4 × 4–4.5 mm, 3-lobed; cocci rounded, smooth to slightly rugose, glabrous; columella 3.2–3.5 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 | 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. |
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. |
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 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. |
Cyathia | peduncle 0.3–0.9 mm. |
peduncle 0–1 mm. |
Euphorbia lurida |
Euphorbia purpurea |
|
Phenology | Flowering and fruiting spring–summer. | Flowering and fruiting spring–fall. |
Habitat | Open pine-oak forests, dry slopes and canyons. | Dry to moist forests and slopes, rock outcrops, swamps or seeps, especially over calcareous rocks. |
Elevation | 1300–2800 m. (4300–9200 ft.) | 50–1100 m. (200–3600 ft.) |
Distribution |
AZ; CA; NM; NV; UT; Mexico (Baja California)
|
DE; MD; NC; NJ; OH; PA; VA; WV |
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 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. 305. | FNA vol. 12, p. 308. |
Parent taxa | Euphorbiaceae > Euphorbia > subg. Esula | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Synonyms | E. palmeri, E. palmeri var. subpubens, E. subpubens, Tithymalus luridus, T. palmeri, T. subpubens | Agaloma purpurea, Galarhoeus darlingtonii |
Name authority | Engelmann: in J. C. Ives, Rep. Colorado R. 4: 26. (1861) | (Rafinesque) Fernald: Rhodora 34: 25. (1932) |
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