Euphorbia polycarpa |
Euphorbia corollata |
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smallseed sandmat |
eastern flowering spurge, flowering spurge, floweringspurge euphorbia |
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Habit | Herbs, perennial, with deep, spreading rootstock. | |
Stems | erect or ascending, usually unbranched, occasionally few branched, solitary or few, previous year's dead stems not persistent, 20–100 cm, glabrous or slightly pilose to villous. |
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Leaves | alternate, ascending; stipules 0.1–0.2 mm; petiole minute or absent; blade oblanceolate, obovate, or elliptic, 25–55 × 5–12 mm, base cuneate to rounded, margins entire, occasionally slightly revolute, apex rounded to subacute, abaxial surface glabrous or pilose to villous, adaxial surface usually glabrous, rarely villous; venation occasionally obscure on small leaves, midvein conspicuous. |
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Involucre | campanulate, 1.2–1.5 × 1.2–1.5(–2) mm, glabrous or moderately puberulent (especially near glands); glands 5, green, reniform, 0.5 × 0.8–1 mm; appendages white, flabellate, 2.5–3.5(–4.5) × 2.5–3.2 mm, entire. |
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Staminate flowers | 20–25. |
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Pistillate flowers | ovary glabrous; styles 0.8–1.4 mm, 2-fid at apex to 1/2 length. |
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Capsules | globose, 2.3–3 × 3.5–4.2 mm, glabrous; columella 2–2.5 mm. |
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Seeds | white or light gray, ovoid, 2.5–2.8 × 2.2 mm, with shallow and coarse depressions; caruncle absent. |
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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 | in terminal pleiochasia, dichasial bracts occasionally whorled or rarely alternate; peduncle (1.5–)5–11(–13) mm (proximal to 70 mm), glabrous. |
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Euphorbia polycarpa |
Euphorbia corollata |
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Phenology | Flowering and fruiting early summer–fall. | |
Habitat | Prairies, open fields, upland woods, glades, barrens, borders of swamps, roadsides, disturbed sites. | |
Elevation | 0–1300 m. (0–4300 ft.) | |
Distribution |
AZ; CA; NV; nw Mexico
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AL; AR; CT; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; ON
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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 corollata is morphologically variable and widely distributed across a large part of eastern North America. The species appears to be expanding its range, as adventive populations have been reported from disturbed habitats at the northern edge of its range in Maine, Massachusetts, Michigan, Minnesota, New Hampshire, South Dakota, and Vermont. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 12, p. 283. | FNA vol. 12, p. 244. |
Parent taxa | Euphorbiaceae > Euphorbia > sect. Anisophyllum | Euphorbiaceae > Euphorbia > sect. Alectoroctonum |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Chamaesyce polycarpa | E. corollata var. molle, E. corollata var. viridiflora, E. marilandica, E. olivacea, Tithymalopsis corollata, T. olivacea |
Name authority | Bentham: Bot. Voy. Sulphur, 50. (1844) | Linnaeus: Sp. Pl. 1: 459. (1753) |
Web links |