Portulaca oleracea |
Portulacaceae |
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common purslane, little hogweed, purslane |
purslane family |
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Habit | Plants annual, glabrous; taproot 2–10 cm. | Subshrubs [shrubs] or herbs, annual, biennial, or perennial, often succulent or fleshy. | ||||||||||||||||||||||||||||||||||||||||
Stems | prostrate, succulent; trichomes at nodes and in inflorescence absent or inconspicuous; branches to 56 cm. |
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Leaves | blades obovate or spatulate, flattened, 4–28 × 2–13 mm, apex round to retuse or nearly truncate; involucrelike leaves 1–4. |
opposite, subopposite, or alternate and sometimes secund, sometimes rosulate or subrosulate, exstipulate (except Portulaca and Talinopsis, with nodal or axillary hairs regarded as stipular); blade margins mostly entire, occasionally dentate to crisped. |
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Inflorescences | axillary or terminal, cymose, racemose, paniculate, or umbellate, sometimes glomerate, spikelike, or with flowers solitary, open to congested. |
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Flowers | 3–10 mm diam.; petals yellow, oblong, 3–4.6 × 1.8–3 mm; stamens 6–12(–20); stigmas 3–6. |
mostly radially symmetric, sometimes slightly irregular (in Montia); sepals 2–9; petals (1–)2–19 or sometimes absent, distinct or connate basally; stamens 1–many, opposite and sometimes basally adnate to petals; gynoecium 2–9-carpelled; ovary 1, superior (half-inferior to inferior in Portulaca), 1-locular throughout or initially plurilocular and becoming 1-locular distally (in Portulaca), placentation basal or free-central, ovules 1-many; style present, sometimes branched, or absent; stigmas 1–9. |
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Fruits | capsular. |
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Capsules | ovoid, 4–9 mm diam. |
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Seeds | black or dark brown, orbiculate or elongate, flattened, 0.6–1.1 mm; surface cells ± smooth, granular, or stellate, with rounded tubercles. |
smooth or sculptured, with or without strophioles or elaiosomes. |
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x | = 4–9, 11, 13, 15, 23. |
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2n | = 18, 36, 54. |
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Portulaca oleracea |
Portulacaceae |
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Phenology | Flowering late spring–early fall. | |||||||||||||||||||||||||||||||||||||||||
Habitat | Fields, waste places | |||||||||||||||||||||||||||||||||||||||||
Elevation | 0-2800 m (0-9200 ft) | |||||||||||||||||||||||||||||||||||||||||
Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK; Europe [Introduced in North America]
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Primarily Southern Hemisphere; poorly represented in Eurasia |
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Discussion | A. P. Simopoulos and N. Salem Jr. (1986) and A. P. Simopoulos et al. (1992) have shown Portulaca oleracea to have the highest content of omega-3 fatty acids and antioxidants of any green leafy vegetable examined to date, suggesting that common purslane should be considered for its nutritional value and not for its weediness. It has long been used as fodder and may have been present in the New World in pre-Columbian times (R. Byrne and J. H. McAndrews 1975). Currently, it is fed to poultry to reduce egg cholesterol. Portulaca oleracea is a highly variable species with worldwide distribution in temperate to warm regions and is the most winter-hardy of all the portulacas. It is a very aggressive weed, one of the ten most noxious weeds worldwide (J. S. Singh and K. P. Singh 1967). As such, many variants have been named (C. D. Legrand 1962) based on seed surface differences, size of seeds, or on variable characters of growth habit, leaf length, and number of stamens. Seven subspecies were recognized by A. Danin et al. (1978): subsp. oleracea, subsp. impolita Danin & H. G. Baker, subsp. granulatostellulata Danin & H. G. Baker, subsp. nicaraguensis Danin & H. G. Baker, subsp. nitida Danin & H. G. Baker, subsp. papillatostellulata Danin & H. G. Baker, and subsp. stellata Danin & H. G. Baker. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 20–30, species ca. 500 (9 genera, 91 species in the flora). The eastern New World species of Portulacaceae seem to have a closer relationship with the African species, and the western New World species a closer one with the Australian species, than the two New World groups have with each other to each other. The outer perianth segments, referred to herein as sepals, are held by some (e.g., T. Eckardt 1976) to be modified bracteoles, the petals then representing the true sepals. However, the traditional interpretation, adopted here and in most North American floras, still finds current support (R. C. Carolin 1987). A comparable situation prevails with respect to the cauline leaves in Claytonia and other genera, which are widely interpreted to be foliaceous bracts (R. C. Carolin 1987); here again, as is appropriate in a descriptive context, the traditional terminology is employed. In Talinopsis and Portulaca, the stipular nature of the nodal or axillary hairs also has been a matter of discussion. The question was revisited by R. Geesink (1969), who denied their stipular origin. The relationships of the family are not a matter of dispute (A. Cronquist 1981; R. C. Carolin 1987); the same cannot be said for the relationships and delimitations of the genera, which have always been labile. They are, at present, the subject of active research, which has led to the current acceptance of Phemeranthus and Cistanthe. Changes in the generic classification are discussed in the treatments of the genera concerned. Because of the uncertain relationships, the genera and species are listed alphabetically. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4. | FNA vol. 4, p. 457. | ||||||||||||||||||||||||||||||||||||||||
Parent taxa | Portulacaceae > Portulaca | |||||||||||||||||||||||||||||||||||||||||
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Synonyms | P. neglecta, P. retusa | |||||||||||||||||||||||||||||||||||||||||
Name authority | Linnaeus: Sp. Pl. 1: 445. (1753) | Adanson | ||||||||||||||||||||||||||||||||||||||||
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