Description: Prostrate or erect, annual or biennial, succulent herbs, covered with glistening vesicular hairs.
Leaves fleshy, semiterete or flat, opposite on lower branches, alternate on flowering branches.
Flowers solitary, axillary, white or with red to pale pink apices. Perianth tubular, lobes 5, 2 large and 3 small, the smaller with membranous margins. Petaloid staminodes many, mostly white; stamens many, to the inside of the staminodes, filaments narrow, often flattened. Ovary inferior or half-inferior, 5-locular; placentation axile; styles 5, free.
Fruit a hygroscopic capsule; seeds numerous.
Distribution and occurrence: World: c. 75 species, along coasts of America, Europe, and Africa. Australia: 3 species (naturalized), N.S.W., Vic., S.A., W.A.
Key is based on: Chinnock, R.J., Stajsic, V. and Brodie, D.J. (2012) Mesembryanthemum guerichianum Pax (Aizoaceae): a weedy alien species new to Australia. Plant Protection Quarterly 27: 83-88.
Text by S. W. L. Jacobs & J. Highet Taxon concept:
| Key to the species | |
1 | Leaves linear, subterete | Mesembryanthemum nodiflorum |
| Leaves ovate to lanceolate | 2 |
2 | Leaves ovate to spathulate, flattened, entire, papillae (bladder cells) on vegetative and floral parts usually <1 mm broad; flowers milky white; petaloid staminodes about as long as sepals | Mesembryanthemum aitonis |
| Leaves ovate to lanceolate, flattened to strongly folded, margins irregularly to strongly undulate; papillae on vegetative and floral parts 1–2 mm broad; flowers white to pinkish, semi-translucent; petaloid staminodes much longer than sepals Back to 1 | 3 |
3 | Plant annual; plant prostrate, to 20 cm high, spreading; stem terete; pedicel 0–5(-12) mm; flowers 10–20(-30) mm diameter | Mesembryanthemum crystallinum |
| Annual or biennial shrub (possibly annual under adverse conditions); plant with erect central stem 30–100 cm high; stem angled-ribbed; pedicel 20–30 mm long; flowers 15–70 mm diameter Back to 2 | Mesembryanthemum guerichianum |
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