In the course of the excavations at the legionary base of Haltern earlier this century, a lead lid some 10.5 cm in diameter was found near to the principia. The lid (PL. XIII) is inscribed EX RADICE BRITANICA (sic).
Seemingly dating some thirty to forty years before the conquest of Britain, this inscription is intriguing. Since the first publication of the lid in 1928 the contents of the vessel to which it belonged have been identified with the herba Britannica which Pliny the Elder described in the following terms:
‘Nor is it beasts alone that are guilty of causing injury; at times waters and regions do the same. When Germanicus Caesar had moved forward his camp across the Rhine, in a maritime district of Germany there was only one source of fresh water. To drink it caused within two years the teeth to fall out and the use of the knee-joints to fail. Physicians used to call these maladies stomaca and scelotyrbe. A remedy was found in the plant called britannica, which is good not only for the sinews and for diseases of the mouth, but also for the relief of quinsy and snake-bite. It has dark, rather long leaves, and a dark root. Its juice is extracted even from the root (sucus eius exprimitur et e radice). The blossom is called vibones; gathered before thunder is heard, and swallowed, it keeps away the fear of quinsy for a whole year. It was pointed out to our men by the Frisians, at that time a loyal tribe, in whose territory our camp lay. Why the plant was so called I greatly wonder,unless perhaps, living on the shore of the British ocean, they have so named the britannica because it is, as it were, a near neighbour of Britain. It is certain that the plant was not named because it grew abundantly in that island: Britain was at that time an independent state.’