The crystals of calcium carbonate, which appear like a bunch of grapes in epidermal cells of the leaves of some plants, are called
Sphaeraphides
Raphides
Otoliths
Cystoliths.
Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
Cystoliths refers to the deposition of calcium carbonate in the epidermal cells of leaves of the plants belonging to the genus Acanthaceae and Urticaceae (stinging nettles).
So, the correct answer is 'Cystoliths'.Hence, the correct answer is option 4.