Euphorbia discoidalis |
Euphorbia blodgettii |
|
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summer spurge |
limestone sandmat |
|
Habit | Herbs, perennial, with spreading rootstock. | Herbs, usually annual, occasionally perennial, with slender to slightly thickened taproot, 3.5 mm diam.. |
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. |
prostrate to decumbent, loosely mat-forming, often rooting at nodes, 10–45 cm, 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. |
opposite; stipules distinct, subulate filiform segments (lower side), or connate forming conspicuous, broad deltate scale (upper side), toothed, 0.5–1 mm, glabrous; petiole 0.7–1 mm, glabrous; blade ovate to oblong-elliptic, 4–10 × 2–5 mm, base asymmetric, subcordate to rounded, margins usually entire, occasionally toothed, apex usually obtuse to rounded, occasionally acute to apiculate, surfaces without red blotch, glabrous; 3-veined from base, only 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. |
turbinate to campanulate, 0.5–0.6 × 0.4–0.6 mm, glabrous; glands 4, red, slightly concave, elliptic-oblong, 0.1 × 0.1–0.3 mm; appendages white to pink, unequal, pair near sinus lunate to oblong, 0.1–0.2 × 0.1–0.3 mm, distal margin entire, crenulate, or irregularly sinuate, other pair sometimes rudimentary, 0–0.1 × 0.1–0.3 mm, distal margin crenulate or entire. |
Staminate flowers | 20–25. |
8–12. |
Pistillate flowers | ovary glabrous or sparsely strigose; styles 0.5–1.1 mm, 2-fid at apex to 1/2 length. |
ovary glabrous; styles 0.3–0.4 mm, 2-fid 1/2 length. |
Capsules | globose, 1.8–3 × 2.5–4.8 mm, glabrous or sparsely strigose; columella 2.3–2.5 mm. |
broadly ovoid, 1.2–1.7 × 1.4–1.9 mm, glabrous; columella 1.2–1.6 mm. |
Seeds | light gray, ovoid, 2 × 1.2–1.3 mm, smooth or with few, very shallow depressions; caruncle absent. |
gray to reddish brown, oblong-ovoid, 4-angled in cross section, 0.9–1.1 × 0.5–0.6 mm, flat or obscurely wrinkled. |
Cyathia | in terminal pleiochasia; peduncle 5–15 mm, filiform, glabrous or very sparsely puberulent to sericeous. |
solitary or in small, cymose clusters at distal nodes of stem or on congested, axillary branches; peduncle 0.4–0.6 mm. |
Euphorbia discoidalis |
Euphorbia blodgettii |
|
Phenology | Flowering and fruiting late spring–fall. | Flowering and fruiting year-round. |
Habitat | Sand hills, pine savannas, woodland borders, open fields with sandy soils. | Coastal sand dunes and disturbed upland sandy areas. |
Elevation | 0–150 m. (0–500 ft.) | 0–20 m. (0–100 ft.) |
Distribution |
AL; FL; GA; LA; MS; TX
|
FL |
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.) |
Euphorbia blodgettii is found only in peninsular Florida. It is closely related to E. garberi, E. porteriana, and E. serpens (Y. Yang and P. E. Berry 2011). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 245. | FNA vol. 12, p. 261. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Alectoroctonum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Tithymalopsis discoidalis | Chamaesyce blodgettii, C. nashii |
Name authority | Chapman: Fl. South. U.S., 401. (1860) | Engelmann ex Hitchcock: Rep. (Annual) Missouri Bot. Gard. 4: 126, plate 13. (1893) |
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