Euphorbia curtisii |
Euphorbia astyla |
|
---|---|---|
Curtis' spurge, Sandhills spurge |
alkali spurge, Pecos spurge |
|
Habit | Herbs, perennial, with spreading rootstock. | Herbs, perennial, with woody or fibrous-fleshy taproot, 5–12 mm thick. |
Stems | erect or ascending, branched, solitary or few, previous year's dead stems not persistent, 20–40 cm, usually glabrous, rarely strigose to sericeous at nodes. |
decumbent, ascending, or erect, few to many emerging from woody crown, 5–25(–50) cm, glabrous. |
Leaves | alternate; stipules to 0.1 mm; petiole to (0–)1–2 mm, glabrous or strigose to sericeous; blade usually linear, occasionally elliptic, rarely ovate, proximal often greatly reduced and often scalelike, 10–30 × 1.5–6 mm, base cuneate, margins entire, occasionally sparsely ciliate, apex rounded or broadly acute, abaxial surface glabrous or sparsely strigose to sericeous, adaxial surface glabrous; venation obscure, only midvein conspicuous. |
opposite; stipules connate into deltate scale, 0.2–0.5 mm, minutely lacerate at apex, glabrous; petiole 0–0.2(–0.3) mm, glabrous; blade orbiculate-reniform to acute-cordate, 2–5(–8) × 2–5(–6) mm, base ± asymmetric, cordate to auriculate, sometimes clasping stem, margins entire, apex narrowly acute, surfaces glabrous; 2- or 3-veined from base, but usually only midvein conspicuous. |
Involucre | campanulate, 1–1.2 × 1.3–1.5(–1.7) mm, glabrous or strigose to sericeous on distal 1/2; glands 5, green, reniform, 0.3 × 0.6 mm; appendages white, semicircular, 0.3–0.4 × 0.6–0.8 mm, entire. |
broadly campanulate, 0.8–1.4 × 0.9–1.4 mm, glabrous; glands 4, yellow-green to brownish, oblong, 0.2–0.3 × 0.5–0.7 mm; appendages white, flabellate to oblong, 0.1–0.2(–0.5) × 0.4–0.8 mm, distal margin entire or dentate-crenate. |
Staminate flowers | 20–25. |
22–26. |
Pistillate flowers | ovary glabrous or sparsely strigose to sericeous; styles 0.6–1.1 mm, 2-fid at apex to 1/2 length. |
ovary glabrous; styles 0.3–0.4 mm, unbranched, thickened-clavate. |
Capsules | globose, 2.5–3.2 × 4.3–5.1 mm, glabrous or sparsely strigose to sericeous; columella 2.4–3.1 mm. |
ovoid and broadly triangular, 1.5–1.9(–2.5) × 1.4–1.6(–2.2) mm, glabrous; columella 1.2–1.8 mm. |
Seeds | usually gray to black, occasionally brown, ovoid-globose, 2.2 × 1.8 mm, smooth; caruncle absent. |
white, oblong, 4-angled in cross section, adaxial faces slightly concave, with long raphe between, 1.5–1.8 × 0.7–1 mm, markedly foveolate, with irregular to ± parallel or anastomosing ridges. |
Cyathia | in terminal pleiochasia (fertile axillary branches occasionally present); peduncle 6.5–17 mm, filiform, glabrous. |
solitary at distal nodes; peduncle 0.3–1(–1.5) mm. |
2n | = 28. |
|
Euphorbia curtisii |
Euphorbia astyla |
|
Phenology | Flowering and fruiting early spring–summer. | Flowering and fruiting late spring–early fall. |
Habitat | Xeric to dry oak or oak-pine scrub of sand hills, pine-oak woodlands, pine-oak savannas. | Desert, grasslands, limestone substrates, usually on very saline or alkaline soils. |
Elevation | 0–200 m. (0–700 ft.) | 700–1100 m. (2300–3600 ft.) |
Distribution |
FL; GA; NC; SC
|
TX; Mexico (Coahuila, Nuevo León) |
Discussion | Euphorbia curtisii is found in the Gulf and Atlantic coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Euphorbia astyla is a specialist on halophytic, alkaline soils and is known in the flora area only in part of Pecos County. The species is closely related to E. jejuna but differs in its sessile or sub-sessile leaves with a cordate-auriculate base and involucral gland appendages that are not deeply lobed or cleft. (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 | E. eriogonoides, Tithymalopsis curtisii, T. eriogonoides | Chamaesyce astyla |
Name authority | Engelmann ex Chapman: Fl. South. U.S., 401. (1860) | Engelmann ex Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 40. (1862) |
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