The cabbage tree. Tī kōuka. That iconic, spiky-leaved, slightly ragged tree that dots the New Zealand landscape – a survivor of swamps and droughts and frosts, a tree that looks like a giant asparagus that decided to become a palm. It is tough, adaptable, almost impossible to kill. But even the cabbage tree had its limits. There was once a coastal giant – a form of cabbage tree that grew taller, thicker, stronger than any alive today. It stood on the dunes, facing the sea, holding the sand together with its massive roots. It was the beach sentinel, and it is gone. A twenty-metre cabbage tree is a spectacular sight – a thick, branching trunk, a crown of spiky leaves that swayed in the wind, a root system that spread deep and wide, binding the sand like a net. It was not just a tree. It was an ecosystem engineer. Its roots stabilised the dunes, preventing erosion. Its fallen leaves built organic matter into the poor sandy soil. Its trunk and branches provided habitat for birds, lizards, and insects. It stood. It grew. It held the shore. For centuries, the coastal giant puhangi formed a living barrier between the land and the sea. It could withstand salt spray, wind, and drought. It flowered prolifically, producing massive panicles of sweet-scented white flowers that fed bees, moths, and birds. Its berries – small, white, juicy – were eaten by birds, which then dispersed its seeds along the coast. It took decades to reach maturity. It reproduced by seed and by root suckers, forming clonal groves that could persist for centuries. A grove of coastal giants would have been a sight to behold – a forest of towering cabbage trees marching along the dunes, their roots intertwined, their crowns swaying together in the wind. Dune clearance and coastal development destroyed it. When Europeans arrived, they cleared the coastal dunes for farming, housing, and roads. The giant puhangi, which needed undisturbed dune systems with space to spread its roots, could not survive in a pasture or a subdivision. Its groves were bulldozed. Its seedlings were eaten by stock. Its root systems were torn apart. Storms delivered the final blow. Without the stabilising roots of the giant puhangi, the dunes began to erode. The remaining trees, weakened by fragmentation, were toppled by wind and waves. By the 1880s, it was gone. The smaller cabbage tree survived. It is more adaptable, able to grow in farmland, swamps, and urban gardens. It is the survivor, the scrappy one, the tree that refused to give up. But the coastal giant puhangi is extinct. A few root casts in sand dunes, a few fragments of wood in coastal deposits, and the memory of a tree that used to hold the shore. We cleared its world. Then we wondered why the beach fell apart.