Idioblast

thumb|Calcium oxalate needles shot out from idioblast (600x magnification)

An idioblast is an isolated plant cell that differs from neighboring tissues. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin, tannin, or pigments etc. Some can contain mineral crystals such as acrid tasting and poisonous calcium oxalate, carbonate, or silica. Any of the tissue or tissue systems of plants can contain idioblasts. Idioblasts are divided into three main categories: excretory, tracheoid, and sclerenchymatous.