These are often called True Fir to distinguish them from the Douglas Fir and a number of other look-alike trees that are similar. The highly scented needles of the Fir contain tannins, making them quite bitter to the taste, and the whole tree contains a volatile oil which can cause mouth, throat and stomach irritation if ingested so it isn't one to have in an area where tortoises could nibble on fallen needles. In addition, trees and shrubs from the Pinaceae family contain various amounts of terpene, which is present in the sticky resin that is produced and acts as a natural pesticide. It is difficult to remove this sticky sap without using harsh cleaning agents, so this is another reason not to have these conifers near tortoise enclosures where the resin could get on their shells.
The cones of Fir trees can be found on top of the branches, looking like little birds on their perch, but a sure way of identifying a True Fir is to pull away a single needle and look for the scar it leaves behind. See also Cedar and Pine.