Euphorbia polycarpa |
Euphorbia pergamena |
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smallseed sandmat |
rocklands spurge, Southern Florida sandmat |
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Habit | Herbs, perennial, with moderately to strongly thickened rootstock. | |
Stems | prostrate to ascending, occasionally mat-forming, terete to slightly flattened, 5–18 cm, glabrous on lower surface, strigillose to sericeous on upper surface. |
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Leaves | opposite; stipules distinct, subulate, better developed on lower side of stem, 0.4–1.3 mm, glabrous or pilose; petiole 0.3–0.5 mm, puberulent, sericeous, or strigillose; blade oblong to ovate, 4–7 × 2–4 mm, base asymmetric, hemicordate, larger side sometimes amplexicaulous, margins entire or serrulate, apex obtuse, surfaces puberulent, sericeous, or strigillose; 3-veined from base, lateral veins inconspicuous. |
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Involucre | campanulate, 1–1.3 × 1–1.1 mm, canescent; glands 4, pinkish, oblong or reniform, 0.2 × 0.4–0.6 mm; appendages white to pink, lunate, unequal, those of proximal glands oblique, 0.6–1 × 1.4–1.6 mm, those of distal glands symmetric, 0.3 × 0.8–0.9 mm, irregularly undulate to incised. |
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Staminate flowers | 15. |
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Pistillate flowers | ovary puberulent, sericeous or strigillose; styles 0.5–1 mm, 2-fid at apex. |
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Capsules | oblate, well exserted from involucre at maturity, 1–1.3 × 1.3–1.8 mm, puberulent, sericeous or strigillose; columella 1 mm. |
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Seeds | whitish to gray, ovoid, 4-angled in cross section, 0.7–0.8 × 0.5–0.6 mm, with 3–4 transverse sulci alternating with low 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 or at nodes of short, congested, axillary shoots; peduncle to 0.5 mm. |
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Euphorbia polycarpa |
Euphorbia pergamena |
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Phenology | Flowering and fruiting year-round. | |
Habitat | Crevices of limestone outcrops in pinelands and pine-palm woods. | |
Elevation | 0–10 m. (0–0 ft.) | |
Distribution |
AZ; CA; NV; nw Mexico
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FL; West Indies (Cuba, Hispaniola) |
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.) |
Euphorbia pergamena is a Florida-listed threatened species known within the flora area from only Miami-Dade and Monroe counties in extreme southern Florida. The species is often included as a subspecies of E. adenoptera (for example, D. G. Burch 1965), but here A. Herndon (1993b) is followed and it is treated as a distinct species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 283. | FNA vol. 12, p. 282. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Anisophyllum |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce polycarpa | Chamaesyce adenoptera subsp. pergamena, C. pergamena, E. adenoptera subsp. pergamena |
Name authority | Bentham: Bot. Voy. Sulphur, 50. (1844) | Small: Bull. Torrey Bot. Club 25: 615. (1898) |
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