Lepidium oleraceum - a threatened herb of coastal Wellington

INTRODUCTION Lepidium oleraceum Sparrm ex G.Forst (Brassicaceae) is a rare thing indeed. Cook’s scurvy grass or nau as it is more commonly known is one of New Zealand’s most famous plants having been harvested by Captain Cook, along with other herbaceous coastal plants, to feed to his crew to protect them from catching scurvy. It may be for that reason the species came top in a 2005 national poll to fi nd New Zealand’s favourite plant. Irrespective, scurvy grass has always been high on New Zealand’s conservation agenda as one of the most endangered elements of the endemic fl ora, and botanists have long acknowledged that to see it in the wild is one of those special botanical moments shared by only a small handful—in the North Island anyway. As we recognise it here, the species is endemic to New Zealand where it is found from the Kermadec and Th ree Kings Island groups, south through the North, South, and Stewart Islands, with a recently discovered (2004) outlier on the Bounty Islands group. With one notable exception (Mangere Island) we regard plants from the Chatham, Antipodes, Snares and Auckland Islands as representing other allied but as yet unnamed potentially distinct species. Through this range the species is now virtually confined to off shore islands, islets and rock stacks. In the Wellington region, as with much of the North Island it has all but vanished (Fig. 1).