Citation: L., Sp. Pl. 688 (1753).

Derivation: There are two explanations of the derivation: 1. Greek mesembria, midday; anthemon, flower; alluding to the majority of species opening in the sun. 2. Greek mesos, middle; embryon, ovary; anthemon, flower; alluding to the position of the ovary. The latter derivation resulted from the discovery of night-flowering species, but necessitated a change in spelling from Mesembrianthemum.

Synonymy: Not Applicable

Common name: None

Description:
Prostrate or procumbent papillose annuals or biennials with opposite or alternate often fleshy flat or terete petiolate or sessile exstipulate leaves.

Flowers solitary, axillary or leaf-opposed or terminal, sessile or pedunculate; perianth lobes 5, unequal, free; stamens many, arising from the staminal tube; staminodes numerous, petaloid, united into a short tube, white and somewhat showy; ovary partly inferior, 5-celled, ovules axile; styles 5, erect, filiform.

Capsule 5-locular, opening when wet by 5 keeled membranous-winged valves; seeds minutely tuberculate.

Distribution:  About 150 African and Asian species. Several grown as garden ornamentals.

Biology: No text

Taxonomic notes: Many species, formerly included in this genus, have been transferred to other genera; those native or naturalised in S.Aust. being Aptenia, Carpobrotus, Disphyma, Drosanthemum, Lampranthus, Micropterum, Psilocaulon, Ruschia and Sarcozona. These genera are sometimes placed in a separate family, the Ficoidaceae or Mesembryanthemaceae.

Key to Species:

1. Leaves flat, usually ovate to spathulate
2. Plant thinly papillose (papillae less than c. 1 mm broad); petaloid staminodes about as long as the perianth	M. aitonis 1.
2. Plant conspicuously densely papillose (papillae at least 1.5 mm broad); petaloid staminodes distinctly longer than the perianth	M. crystallinum 2.
1. Leaves subterete, linear	M. nodiflorum 3.

Author: Not yet available