The deliberate introduction to Australia of the shrub genus Pentzia (Asteraceae) and its subsequent persistence and spread.

Abstract

Pentzia is a predominantly southern African genus of low shrubs, many of which are important fodder plants for sheep in semi-arid and arid areas. Attempts since 1869 to introduce Pentzia incana to south-eastern Australia for sheep fodder are described. One of these, near Koonamore in north-eastern South Australia, was temporarily successful there and may have led to the only extant stands in Australia – two well-established populations at Mount Serle in the northern Flinders Ranges. These events are related to the biology of the species and to similar events concerning the deliberate introduction of the species to Arizona. These data are discussed in terms of current ideas about plant introduction, dispersal, invasion and the concept of sleeper weeds. Pentzia globosa is currently known from a single stand in Australia, at Bundaleer Forest in the Mid North of South Australia. The history of this occurrence is briefly discussed. For both species, it is concluded that regular monitoring is needed in case of rapid spread and that further data are needed on the extent to which they exhibit weedy behaviour in southern Africa.