Flowering megaherbs, Campbell Island, Southern Ocean

Campbell Island lies in the Southern Ocean approximately 700 kilometres south of New Zealand, a lonely speck of land surrounded by thousands of square kilometres of storm-ravaged subantarctic ocean. The island is the dissected remnant of an ancient volcanic centre that has subsequently been severely eroded by the sea and also by wind, rain, and the sculpting action of frost and ice during several ice ages. What’s now left of Campbell Island covers a mere 11,000 hectares, a small but crucial sanctuary for many rare species of flora and fauna. In recognition of its special importance to conservation, Campbell Island and its surrounding islets were declared a reserve in 1954.

Peculiar to Campbell Island and a few other tiny subantarctic islands in the New Zealand region are the so-called ‘megaherbs’, giant herbaceous plants which flower in spectacular fashion in mid-late summer. The large leaves are thought to be a result of the almost permanently cloudy conditions experienced at this southerly latitude (about 52º South), where low light levels have prompted some plants, such as Pleurophyllum speciosum, to grow extra-large leaves to increase their ability to photosynthesise.

This example of Pleurophyllum, with its dinner plate-sized corrugated leaves and large daisy-like flowers, was photographed on an exposed ridge overlooking Northwest Bay, near Mt Lyall.