XVI International Botanical Congess

Geleznowia verrucosa Turcz. (Rutaceae) is a monotypic, but morphologically diverse species, endemic to the sandplains north and east of Perth Western Australia. Disjunct populations are generally small with three forms distinguishable by leaf and flower shape and flower abundance, forms rarely co-occur. An allozyme investigation of 19 widely distributed populations concurred with genetically depauperate expectations of endemic taxa. Restricted distribution, bottlenecks and/or founder effects and small population size have probably contributed to the low levels of genetic diversity observed. However, differences in the partitioning of genetic diversity between the forms suggest that the small- and large-flowered forms represent distinct taxa. Higher levels of divergence between the intermediate form populations suggest that this form is of hybrid origin and has arisen through a series of hybrid events between the small and large forms.