This Crucifer, whose rather hard root has the taste of mustard, was sometimes called in French _cran_, or _cranson de Bretagne_. This was an error caused by the old botanical name _Armoracia_, which was taken for a corruption of _Armorica_ (Brittany). _Armoracia_ occurs in Pliny, and was applied to a crucifer of the Pontine province, which was perhaps _Raphanus sativus._ After I had formerly[46] pointed out this confusion, I expressed myself as follows on the mistaken origin of the species:—_Cochlearia Armoracia_ is not wild in Brittany, a fact now established by the researches of botanists in the west of France. The Abbé Delalande mentions it in his little work, entitled _Hœdic et Houat_,[47] in which he gives so interesting an account of the customs and productions of these two little islands of Brittany. He quotes the opinion of M. le Gall, who, in an unpublished flora of Morbihan, declares the plant foreign to Brittany. This proof, however, is less strong than others, since the south coast of the peninsula of Brittany is not yet sufficiently known to botanists, and the ancient Armorica extended over a portion of Normandy where the wild horse-radish is now found.[48] This leads me to speak of the original home of the species. English botanists mention it as wild in Great Britain, but are doubtful about its origin. Watson[49] considers it as introduced by cultivation. The difficulty of extirpating it, he says, from places where it is cultivated, is well known to gardeners. It is therefore not surprising that this plant should take possession of waste ground, and persist there so as to appear indigenous. Babington[50] mentions only one spot where the species appears to be really wild, namely, Swansea. We will try to solve the problem by further arguments. _Cochlearia Armoracia_ is a plant belonging to the temperate, and especially to the eastern regions of Europe. It is diffused from Finland to Astrakhan, and to the desert of Cuman.[51] Grisebach mentions also several localities in Turkey in Europe, near Enos, for instance, where it abounds on the sea-shore.[52] The further we advance towards the west of Europe, the less the authors of floras appear sure that the plant is indigenous, and the localities assigned to it are more scattered and doubtful. The species is rarer in Norway than in Sweden,[53] in the British Isles than in Holland, where a foreign origin is not attributed to it.[54]