Mesembryanthemum crystallinum leaves big and small

The sometimes large, fleshy Mesembryanthemum crystallinum leaves may be lettuce-like and usually folded in along their midribs, the margins wavy. Leaves of several sizes are often seen on younger plants. The dark green to dull green blades are sometimes suffused with purple.

The water cells on the lower leaf surfaces are rich in saponins, chemical substances containing toxic glucosides that foam in water, resembling soap, and add a bitter taste. The saponins occurring in various plant species, including soapworts, serve as a deterrent to herbivores. This is one of the chemical warfare defence mechanisms found in plant world (Van Rooyen and Van Rooyen, 2019; Grenier, 2019; Smith, et al, 2017; Smith, et al, 1998; Manning and Goldblatt, 1997; iNaturalist; Wikipedia).