I just discovered this wonderful site! Medieval drawings and information on rare beasties!
“The peridexion tree grows in India. Doves gather in the tree because they like the sweet fruit, and because there they are safe from the dragon. The dragon hates the doves and would harm them if it could, but it fears the shadow of the peridexion tree and stays on the unshaded side of it. The doves that stay in the shadow are safe, but any who leave it are caught and eaten by the dragon.” Medieval Bestiary