Euphorbia indivisa |
Euphorbia ocellata |
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royal sandmat |
Contura Creek sandmat, Contura Creek spurge, valley spurge |
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Habit | Herbs, annual or short-lived perennial, with slender taproot to thickened and woody rootstock. | Herbs, annual, with taproot. | ||||
Stems | prostrate, usually mat-forming, terete to slightly flattened, 40 cm, lower surface glabrous, upper surface strigillose, pilose or villous. |
prostrate, 10–35 cm, glabrous or pilose. |
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Leaves | opposite; stipules distinct, entire or divided into 3–4 subulate to filiform segments, 0.8–2 mm, usually pilose, rarely glabrous; petiole 0.5–1 mm, pilose to villous; blade oblong, ovate or narrowly obovate, 3–10(–12) × 2–6 mm, base strongly asymmetric, hemicordate, margins serrulate, apex obtuse to subacute, surfaces glabrous or slightly pilose; 3-veined from base, often only midvein conspicuous. |
opposite; stipules distinct, subulate, 0.5–1.6 mm, glabrous or pilose; petiole 0.3–2 mm, glabrous or pilose; blade ovate to deltate or falcate, 2.3–13 × 1.5–6 mm, base asymmetric, usually cordate, rarely rounded, margins occasionally reddish, entire, often revolute, apex acute to obtuse, occasionally mucronate, surfaces glabrous or pilose; midvein conspicuous, lateral veins frequently visible abaxially. |
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Involucre | narrowly turbinate, 1–1.2 × 0.4–0.7 mm, pilose; glands 4, yellow to pink, unequal, proximal pair oblong or linear, 0.1 × 0.3–0.4(–0.6) mm, distal pair oblong or subcircular, 0.1 × 0.1–0.2 mm; appendages pink to reddish, unequal, on proximal glands oblique, 0.4–0.8(–1) × 0.8–1.4(–2) mm, on distal glands symmetric, 0.2–0.5 × 0.2–0.5 mm, slightly undulate to slightly crenate. |
campanulate, 1–2.5 × 1.3–2.4 mm, glabrous or pilose; glands 4, yellow becoming deep red, elliptic or oblong to orbiculate, 0.4–0.6 × 0.5–0.7 mm; appendages absent or whitish, orbiculate, 0.1–0.2 × 0.3–0.5 mm, distal margin entire. |
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Staminate flowers | 5–15. |
30–70. |
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Pistillate flowers | ovary pilose to strigillose in parts, glabrous in other parts; styles 0.8–1.3 mm, usually unbranched, rarely 2-fid at apex, filiform. |
ovary glabrous or pilose; styles 0.4–0.5 mm, 2-fid at apex. |
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Capsules | ovoid-triangular, 1.2–1.5 × 1–1.4 mm, pilose to strigillose in parts, glabrous in other parts; columella 1–1.3 mm. |
subglobose to broadly ovoid, 1.4–2.7 × 1.9–3.1 mm, glabrous or pilose; columella 1.4–2 mm. |
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Seeds | brown to light gray, ovoid, 4-angled in cross section, 0.8–1 × 0.4–0.5 mm, with 4 or 5 deep transverse sulci alternating with low transverse ridges. |
whitish gray to black, ovoid to oblong, terete to bluntly subangled in cross section, 1.1–1.7 × 0.8–1.3 mm, rugose or smooth. |
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Cyathia | usually in small cymose clusters on congested, axillary branches; peduncle rudimentary or to 0.2 mm. |
solitary at distal nodes; peduncle 0.9–2.2 mm. |
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Euphorbia indivisa |
Euphorbia ocellata |
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Phenology | Flowering and fruiting summer–fall. | |||||
Habitat | Grasslands, oak forests, oak-mesquite woodlands, oak-juniper communities, rarely entering desert scrub. | |||||
Elevation | 1000–2000 m. (3300–6600 ft.) | |||||
Distribution |
AZ; NM; TX; Mexico
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AZ; CA; ID; NV; UT
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Discussion | Euphorbia indivisa is characteristic of grasslands and oak woodlands from extreme western Texas to southeastern Arizona. The species is often treated as a synonym of E. dioeca Kunth, but the two species are readily separable on the basis of their seeds. The seeds of E. indivisa possess deep transverse sulci, whereas those of E. dioeca are merely rippled or with low transverse ridges. Euphorbia dioeca is a weedy species that occurs widely throughout tropical America but has yet to be encountered within the flora area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 12, p. 273. | FNA vol. 12, p. 279. | ||||
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | E. dioeca var. indivisa, Chamaesyce indivisa | Chamaesyce ocellata | ||||
Name authority | (Engelmann) Tidestrom: Proc. Biol. Soc. Wash. 48: 40. (1935) | Durand & Hilgard: Pl. Heermann., 46. (1854) | ||||
Web links |