Calcium phosphate is a typical component of teeth and bones. It has recently been shown that plants of the rock nettle family also use this very hard mineral in their “teeth” to defend themselves against their animal enemies. Botanists of Bonn University have now demonstrated that calcium phosphate is a lot more widespread in plants than previously suspected. Even thal cress (Arabidopsis thaliana) uses trichomes hardened with an incrustation of this biomineral to defend itself against enemies such as aphids. The results have now been published online first in the scientific journal “Planta”. The print version will be published in January.