Morphometric study of a hybrid population of Acacia verniciflua and A. aspera (Acacia subgenus phyllodineae)

Abstract

Hybrids between the common variant of Acacia verniciflua A.Cunn. and Acacia aspera Lindl. are reported from central Victoria, in remnant vegetation in the median strip of the Hume Highway, south of Benalla. Plants of both species and suspected hybrids were sampled and mapped along a belt transect. Morphological pattern analysis, based largely on phyllode characters and using ordination and agglomerative classification techniques, confirmed a hybrid population of plants intermediate between A. verniciflua and A. aspera and possible backcrosses to one or other of the parent species. Scanning electron microscopy revealed that hybrids had density of simple hair and morphology of glandular trichomes intermediate between the two parents. The site has been disturbed, which may account for the hybrid swarm.