Euphorbia discoidalis |
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summer spurge |
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Habit | Herbs, perennial, with spreading rootstock. |
Stems | erect or ascending, unbranched, solitary or few, previous year's dead stems not persistent, 45–70 cm, usually densely puberulent to sericeous, rarely glabrous. |
Leaves | alternate; stipules to 0.1 mm; petiole (0–)1–2 mm (or absent), densely puberulent; blade usually linear, rarely ovate, 25–55 × 1.5–4 mm, base cuneate, margins entire, revolute, apex rounded, abaxial surface glabrous or puberulent to sericeous, adaxial surface glabrous; venation often obscure on smaller leaves, midvein conspicuous. |
Involucre | campanulate, 1.2–1.4 × 1.2–2 mm, sparsely to densely puberulent; glands 5, green, reniform, 0.2–0.3 × 0.5–0.6 mm; appendages white, orbiculate to oblong, (0.5–)1–1.7 × 1–1.5 mm, entire. |
Staminate flowers | 20–25. |
Pistillate flowers | ovary glabrous or sparsely strigose; styles 0.5–1.1 mm, 2-fid at apex to 1/2 length. |
Capsules | globose, 1.8–3 × 2.5–4.8 mm, glabrous or sparsely strigose; columella 2.3–2.5 mm. |
Seeds | light gray, ovoid, 2 × 1.2–1.3 mm, smooth or with few, very shallow depressions; caruncle absent. |
Cyathia | in terminal pleiochasia; peduncle 5–15 mm, filiform, glabrous or very sparsely puberulent to sericeous. |
Euphorbia discoidalis |
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Phenology | Flowering and fruiting late spring–fall. |
Habitat | Sand hills, pine savannas, woodland borders, open fields with sandy soils. |
Elevation | 0–150 m. (0–500 ft.) |
Distribution |
AL; FL; GA; LA; MS; TX
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Discussion | M. J. Huft (1979) remarked that Euphorbia discoidalis is uncommon west of Alabama and referred many narrow-leaved specimens from Louisiana and Texas to E. corollata. K. R. Park (1998) included them in an expanded E. discoidalis, and that is followed here. The western populations can be distinguished from E. corollata by their shorter involucral gland appendages and revolute leaf margins. Further study of these western populations is warranted. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 245. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | |
Synonyms | Tithymalopsis discoidalis |
Name authority | Chapman: Fl. South. U.S., 401. (1860) |
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