Euphorbia setiloba |
Euphorbia astyla |
|
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fringe spurge, shaggy spurge, Yuma sandmat |
alkali spurge, Pecos spurge |
|
Habit | Herbs, annual, with slender taproot. | Herbs, perennial, with woody or fibrous-fleshy taproot, 5–12 mm thick. |
Stems | prostrate, mat-forming, 5–50 cm, villous with glistening glandular hairs. |
decumbent, ascending, or erect, few to many emerging from woody crown, 5–25(–50) cm, glabrous. |
Leaves | opposite; stipules distinct, filiform, rudimentary to 0.2 mm, glabrous or sparsely villous with glistening glandular hairs; petiole 0.5–1.5 mm, villous; blade oblong, ovate, or elliptic, 3–7 × 2–4 mm, base asymmetric, rounded, margins entire, apex obtuse, surfaces villous; weakly 3-veined from base, commonly 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 or urceolate, 0.7–1 × 0.5–0.8 mm, villous; glands 4, red to pink, oblong to slightly reniform, 0.1–0.2 × 0.2–0.3 mm; appendages white to pink, deeply incised into 3–6 triangular to subulate, attenuate, acute segments, 0.3–0.6 × 0.6–1 mm, segments 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 | 3–7. |
22–26. |
Pistillate flowers | ovary villous; styles 0.3–0.4 mm, 2-fid 1/2 length. |
ovary glabrous; styles 0.3–0.4 mm, unbranched, thickened-clavate. |
Capsules | subglobose to ovoid, 1–1.2 mm diam., villous; columella 0.9–1.1 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 | pink to light gray, narrowly ovoid, 4-angled in cross section, 0.8–1 × 0.5–0.6 mm, dimpled or with faint transverse ridges that do not pass through abaxial keel. |
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 | solitary at distal nodes, nodes often congested toward tips of branches; peduncle 0.2–1.6 mm. |
solitary at distal nodes; peduncle 0.3–1(–1.5) mm. |
2n | = 28. |
|
Euphorbia setiloba |
Euphorbia astyla |
|
Phenology | Flowering nearly year-round in response to sufficient moisture. | Flowering and fruiting late spring–early fall. |
Habitat | Desert scrub, blackbrush scrub, Joshua tree woodlands, grasslands, often in sandy areas. | Desert, grasslands, limestone substrates, usually on very saline or alkaline soils. |
Elevation | 20–1600 m. (100–5200 ft.) | 700–1100 m. (2300–3600 ft.) |
Distribution |
AZ; CA; NM; NV; TX; UT; Mexico (Baja California, Baja California Sur, Chihuahua, Durango, Sinaloa, Sonora)
|
TX; Mexico (Coahuila, Nuevo León) |
Discussion | 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. 288. | FNA vol. 12, p. 261. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Synonyms | Chamaesyce setiloba | Chamaesyce astyla |
Name authority | Engelmann: in War Department [U.S.], Pacif. Railr. Rep. 5(2): 364. (1857) | Engelmann ex Boissier: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 40. (1862) |
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