Lepidium arbuscula

Anaunau is a critically endangered shrub endemic to New Zealand, belonging to the mustard family (Brassicaceae). This compact, woody plant typically grows 30-60 centimeters tall with small, fleshy leaves adapted to coastal conditions. Like other Lepidium species, it produces clusters of tiny white flowers followed by small seed pods. The species plays a role in coastal ecosystem stability, helping to bind soil and providing habitat structure in its native environment.

Anaunau is restricted to New Zealand's coastlines, where it historically occupied rocky shores, cliff faces, and coastal terraces. The species requires well-drained soils and can tolerate salt spray and strong winds typical of exposed coastal environments. Its natural range has become severely fragmented, with populations now confined to scattered locations.

The primary threats to anaunau include habitat destruction from coastal development, competition from invasive plant species, and browsing by introduced mammals such as rabbits and livestock. Coastal erosion and storm damage also impact remaining populations. The species' naturally fragmented distribution makes it particularly vulnerable to local extinctions.

Conservation efforts include habitat protection at key sites, propagation programs to maintain genetic diversity, and restoration plantings in suitable locations. Some populations receive protection through reserve status, and botanical institutions maintain seed collections as genetic insurance.

The current outlook for anaunau remains precarious. With extremely limited wild populations and ongoing habitat pressures, the species faces a high risk of extinction without sustained conservation intervention. Success depends on continued habitat protection and active management of remaining sites.