Tough, leathery-leaved shrubs cling to the mountain slopes, their branches twisted by the wind, their white or pink bells blooming in the summer snowmelt. They are the last green things before the rocks. But there was once an alpine heath that grew taller than any alive today – a shrub that reached the height of a small tree, its trunk thick and woody, its leaves long and tough. It formed dense thickets on the alpine ridges, a green band between the treeline and the rocks. It was the giant alpine heath, and it is gone. A four-metre shrub on an alpine ridge is a giant – a woody tower in a world of low-growing herbs and mosses. Its thickets provided shelter for smaller plants, habitat for alpine birds and lizards, and stability for the mountain slope. Its roots spread wide and deep, holding the thin soil in place. It was the engineer of the alpine zone, the plant that made the mountain habitable. It built the alpine soil. In the harsh alpine environment, soil is precious – a thin layer of organic matter over rock, easily eroded. The giant alpine heath captured wind-blown dust, added its own fallen leaves to the ground, and held everything together with its roots. Its thickets trapped snow, releasing it slowly in spring, providing water for the plants below. Its flowers – probably white or pink, like its living relatives – bloomed in summer, feeding alpine insects and moths. Its seeds were dispersed by wind, but germination was slow, and seedlings grew at a glacial pace. It took decades to reach maturity. It flowered irregularly, producing seeds only in good years. That strategy works when the mountain is stable. It fails when the grazers arrive and the soil begins to slip. Introduced grazers and erosion destroyed it. European settlers introduced goats, chamois, and thar to the mountains. These animals love alpine shrubs. They ate the leaves, stripped the bark, trampled the roots. A slow-growing shrub that takes decades to reach maturity cannot survive annual browsing. The erosion that followed was catastrophic. Without the shrub's roots to hold them, the mountain slopes began to slip. The thin soil washed away, taking the seeds and seedlings with it. Fire may have delivered the final blow. Hunters burned the alpine scrub to clear hunting grounds. The giant heath, with its woody stems and resinous leaves, burned readily. The old plants, already stressed by browsing and erosion, could not regenerate after fire. By the 1920s, it was gone. The last plants were probably eaten by a goat or burned by a hunter's fire. No one knew they were the last. The smaller heaths survived. Dracophyllum traversii and its relatives still cling to the alpine ridges – shorter, tougher, more wind-battered. They are the survivors, the low-growing ones, the plants that kept their heads down. But the giant alpine heath is extinct. A few fragments of wood in a museum drawer, a few pollen grains in a mountain bog, and the memory of a shrub that used to tower over the alpine ridges. We brought the grazers. Then we wondered why the mountain fell apart.