feeding on or living in limestone
• (a.) Eroding, or eating into, limestone.
Cal·civ'o·rous adjective [ Latin calx lime + vorare to devour.] Eroding, or eating into, limestone. 
calcivore, calcivorous, calcivory A reference to plants living on limestone or in soils rich in calcium salts. Applied to forms such as some lichens and Mollusca that erode or borrow in limestone.