Euphorbia polycarpa |
Euphorbia villifera |
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smallseed sandmat |
hairy spurge |
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Habit | Herbs, annual or perennial, with slender taproot or thickened, woody rootstock. | |
Stems | usually erect to ascending, rarely prostrate to decumbent, 10–30 cm, papillate, usually villous, sometimes glabrous. |
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Leaves | opposite; stipules distinct, filiform, usually undivided, rarely divided into 2–3 segments), 0.3–0.7 mm, glabrous, papillate; petiole 0.6–1.8 mm, usually villous, rarely glabrous; blade ovate, 3–12 × 2–10 mm, base asymmetric, rounded to slightly cordate, margins entire or serrulate, apex acute to obtuse, surfaces usually villous, rarely glabrous; only midvein conspicuous. |
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Involucre | campanulate, 0.7–0.9 × 0.6–1 mm, glabrous or pilose; glands 4, pink, oval, oblong, or trapezoidal, 0.1–0.2 × 0.2 mm; appendages white to pink, flabellate, oblong, ovate, or nearly rectangular, 0.2–0.4 × 0.2–0.6 mm, distal margin entire. |
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Staminate flowers | 10–25. |
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Pistillate flowers | ovary glabrous; styles 0.3–0.5 mm, 2-fid 1/2 to nearly entire length. |
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Capsules | oblate-deltoid, cocci often elongated and terminating in an empty portion, 1.5–2 × 2.1–3.1 mm, glabrous; columella 0.9–1.5 mm. |
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Seeds | gray-brown to red-brown, ovoid-oblong, weakly 4-angled in cross section, 1–1.4 × 0.6–0.8 mm, smooth, faintly rugose, or with inconspicuous transverse ridges. |
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Euphorbia | polycarpa is a highly variable species distributed throughout the Baja California peninsula, eastern Sonora, and the arid southwestern United States from southwestern Arizona to southern Nevada and central California. |
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l | . |
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c | . |
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Wheeler | (1941) divided the species into seven varieties, the majority of which occur in Baja California Sur. |
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He | reported two of these for the United States: var. hirtella and var. polycarpa. |
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Variety | hirtella, as the name suggests, was applied to hairy plants. |
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However | , it is here treated as a synonym of var. polycarpa, because variation in pubescence shows no geographic segregation and ranges along a continuum from glabrous or sparsely to densely hairy, and because glabrous and hairy branches can occur on the same individual. |
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Cyathia | solitary at distal nodes; peduncles 0–1.8 mm. |
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Euphorbia polycarpa |
Euphorbia villifera |
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Phenology | Flowering and fruiting early spring–early winter. | |
Habitat | Riparian forests with walnuts and sycamores, juniper woodlands, pine-oak woodlands, mostly on limestone substrates. | |
Elevation | 100–1400 m. (300–4600 ft.) | |
Distribution |
AZ; CA; NV; nw Mexico
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TX; Mexico; Central America |
Discussion | Varieties 5 (1 in the flora). Some of the varieties occurring in Mexico are highly divergent and appear to be sufficiently distinct to merit recognition as species. However, within the flora area, Euphorbia polycarpa is relatively uniform, and the only noteworthy variation involves the size of the involucral gland appendages. In the portion of the California Floristic Province occupied by E. polycarpa (Los Angeles, Orange, western Riverside, western San Diego, and Ventura counties) the appendages are conspicuously larger than those of plants throughout the remainder of its range in the southwestern United States (0.4–1.2 versus 0.1–0.3 mm). Large-appendaged plants are also common in Baja California and correspond well with the type collection. The taxonomic significance of this variation is not clear at this time, and the small-appendaged plants may merit segregation as an infraspecific taxon. However, no formal changes are proposed, awaiting a comprehensive review of the species throughout its range. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Although Euphorbia villifera has been reported from New Mexico (W. C. Martin and C. R. Hutchins 1980), no vouchers to verify its presence there were located. In Texas, E. villifera is known from the Edwards Plateau westward into the trans-Pecos region. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 283. | FNA vol. 12, p. 293. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce polycarpa | Chamaesyce stanfieldii, C. villifera, E. stanfieldii, E. villifera var. nuda |
Name authority | Bentham: Bot. Voy. Sulphur, 50. (1844) | Scheele: Linnaea 22: 153. (1849) |
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