Mesembryanthemum crystallinum (the common, 'crystalline' or 'crystallinum' iceplant, or simply 'iceplant') is a species of annual/perennial, succulent flowering plant in the "mesemb" genus of the Aizoaceae family.

[4] Like many salt-tolerant plants, M. crystallinum accumulates salt throughout its life, in a gradient from the roots to the shoots, with the highest concentration stored in epidermal bladder cells.

The salt is released by leaching once the plant dies, resulting in a detrimental osmotic environment preventing the growth of other, non-salt-tolerant species while allowing M. crystallinum seeds to germinate.

[3] In M. crystallinum, the number of seeds produced depends on whether CAM has been activated (C3 metabolism is more efficient) and the size the plant has grown to in its juvenile growth phase.

It can tolerate nutritionally poor or saline soils (halophile), and grows well in disturbed sites such as roadsides, rubbish dumps and homestead yards.

[5][6][7] Its ability to grow in poor quality or saline soils and preference for disturbed areas are traits shared by many invasive plants which enable them to outcompete native species.