Natural propagation of orange buddleia (Buddleja madagascariensis Lamarck) in eastern Australia

摘要

The exotic ornamental scrambling bramble orange buddleia, Buddleja madagascariensis, forms dense impenetrable thickets in various forest types in eastern Australia. The plant is widespread throughout the world and weedy in many locations. In Australiait is found growing in patches in the national parks of the Border Ranges between Queensland and New South Wales where it is of great concern for the damage it might do to the rainforest where it grows. B. madagascariensis is sterile in Australia and noseeds have been seen on the plant despite extensive searches of plants in eastern Australia nor reported in the literature. It is therefore curious that the plant is able to establish and grow in the midst of national parks apparently distant from any source of infestation. This study investigates the hypothesis that B. madagascariensis can be spread by stem sections that may be carried by birds, water, or perhaps people, and that simply casting them upon the ground is sufficient to allow them to rootand grow. Stems of B. madagascariensis were placed on the ground in rainforest under various circumstances and it was found that a small proportion of stems can root and grow under a wide range of conditions.