Leaf ontogeny and morphology in Acacia Mill. (Mimosaceae)

Abstract

The recently redefined genus Acacia consists of more than 1000 species, nearly all of which are endemic to Australia. Acacia foliage is highly variable and all species exhibit heteroblastic leaf development to some extent as seedlings, with a typical progression from pinnate to bipinnate leaves in the first few seedling nodes followed in most species by the transition to phyllodes. Although phyllodes occur in several plant families, the Acacia phyllode is unique and its structure, development and the genetic processes involved in its formation are not well understood. Despite its significance for classification, the developmental homology of this character remains uncertain. Modern microscop..