MAZUS ARENARIUS (SCROPHULARIACEAE), A NEW, SMALL-FLOWERED, AND RARE SPECIES SEGREGATED FROM M-RADICANS

Mazus arenarius Heenan, P.N.Johnson et C.J. Webb is described from sou thern New Zealand. It is a perennial, rhizomatous herb from coastal sa nd dune hollows and herbfields in south-east Otago, Southland, and Ste wart Island. Mazus arenarius has previously been included in M. radica ns but is distinguished by its uniformly coloured green-brown or purpl e-brown leaves which lack blotches, a short peduncle, smaller flowers with the lower corolla lobes with a retuse apex and horizontal upper c orolla lobes, an obtuse and rounded fruit apex, and usually smaller se ed. The ecology is described and a list presented of 44 native and 16 naturalised species associated with M. arenarius at the False Islet an d Three Sisters Dune populations. Mazus arenarius has been recorded fr om only 14 sites, and as it is never common it is classified as a rare plant.