Description: Succulent prostrate to decumbent or erect annual or perennial herbs, often with thickened taproot.
Leaves opposite or alternate, mostly subsessile, succulent, terete or flat, acute to obtuse or truncate, entire, glabrous; axillary hairs absent or short and inconspicuous or long and appearing woolly.
Flowers in axillary or terminal cymes, or in 2–30-flowered terminal heads, with hairs in the axils of bracts between the flowers, surrounded by 3–20 involucral leaves. Sepals united at base into a tube which is fused to lower part of ovary. Petals 4–6, fused at the base. Stamens 8–numerous. Ovary half-inferior, ovoid to globose, ovules numerous; stigmas 3–7, on a style.
Capsule dehiscing by a circumsciss split below the summit of the ovary, the operculum falling off with sepals and withered petals, remaining base cup- or saucer-shaped; seeds numerous, mostly subobovoid to lenticular or subreniform, often tuberculate.
Distribution and occurrence: World: 100–125 species tropical, subtropical & temperate regions. Australia: c. 20 species, all States.
Text by J. G. West
Taxon concept:
| | Key to the species | |
| 1 | Leaves opposite, circular or broad-ovate; flowers on pedicels 3–6 mm long | Portulaca bicolor |
| Leaves alternate, linear, lanceolate, or obovate to oblanceolate, never circular or broad-ovate; flowers sessile | 2 |
| 2 | Leaves obovate to oblanceolate, usually more than 4 mm wide, dorsiventrally flattened; axillary hairs inconspicuous, to 1 mm long | 3 |
| Leaves linear, lanceolate or rarely oblanceolate, less than 4 mm wide, terete or flattened; axillary hairs conspicuous, usually more than 5 mm long
Back to 1 | 4 |
| 3 | Petals 10–17 mm long, twice as long as the sepals; stamens more than 20 | Portulaca intraterranea |
| Petals 4–7 mm long, scarcely exceeding the sepals; stamens less than 20
Back to 2 | Portulaca oleracea |
| 4 | Leaves linear, lanceolate or rarely oblanceolate, dorsiventrally flattened; petals pink | Portulaca pilosa |
| Leaves linear, terete; petals yellow
Back to 2 | 5 |
| 5 | Petals 4–10 mm long | Portulaca filifolia |
| Petals 15–20 mm long
Back to 4 | Portulaca grandiflora |
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