Euphorbia polycarpa |
Euphorbia serrata |
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smallseed sandmat |
saw tooth spurge, saw-tooth or tooth or serrate spurge, serrate spurge |
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Habit | Herbs, perennial, with thick rootstock. | |
Stems | erect, branched, 10–70 cm, glabrous. |
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Leaves | petiole absent; blade lanceolate, ovate-lanceolate, linear, or linear-lanceolate, 10–70 × 2–20 mm, base acute or obtuse, margins irregularly serrate, apex acute to obtuse, surfaces glabrous; venation inconspicuous, only midvein prominent. |
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Involucre | campanulate, 2–4 × 1.2–3 mm, glabrous; glands 4–5, elliptic, ovate, or suborbiculate, 1.2–1.8 × 1.5–2.7 mm; horns absent or slightly divergent, 0–0.6 mm. |
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Staminate flowers | 20–40. |
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Pistillate flowers | ovary glabrous; styles 1–2 mm, 2-fid. |
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Capsules | subovoid, 4.5–6 × 4–5 mm, 3-lobed; cocci rounded, smooth occasionally slightly puncticulate, glabrous; columella 4–4.5 mm. |
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Seeds | grayish, cylindric, 2.5–3.1 × 1.7–2 mm, smooth or slightly dotted; caruncle subconic, lobed, 1–1.5 × 0.5–1 mm. |
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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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Cyathial | arrangement: terminal pleiochasial branches 3–5, each 1–3 times 2-branched; pleiochasial bracts ovate-lanceolate, usually shorter and wider than distal leaves; dichasial bracts distinct, ovate or deltate, base obtuse to cordate, margins irregularly dentate, apex acute, or obtuse, mucronate; axillary cymose branches 0–3. |
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Cyathia | peduncle 1–5 mm. |
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Euphorbia polycarpa |
Euphorbia serrata |
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Phenology | Flowering and fruiting spring–fall. | |
Habitat | Waste places, disturbed sites, roadsides, fields, pastures. | |
Elevation | 0–300 m. (0–1000 ft.) | |
Distribution |
AZ; CA; NV; nw Mexico
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CA; Europe; Atlantic Islands (Macaronesia) [Introduced in North 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.) |
Euphorbia serrata, native to the western Mediterranean region of Europe and Macaronesia, is listed as a noxious weed by the state of California. In the flora area, it has been found in coastal counties from Sonoma to Monterey counties; attempts to eradicate it may have been successful. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 283. | FNA vol. 12, p. 309. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > subg. Esula |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce polycarpa | Galarhoeus serratus, Tithymalus serratus |
Name authority | Bentham: Bot. Voy. Sulphur, 50. (1844) | Linnaeus: Sp. Pl. 1: 459. (1753) |
Web links |