Aspects of Phyllode Anatomy in Some Australian Phyllodinous Acacias, With Particular Regard to Stickiness

Abstract

Phyllodes of species of Acacia from the sections Julflorae, Plurinerves, Lycopodiifoliae and Phyllodineae are described in respect of the disposition of the stomates relative to the phyllode surface, size of the substomatal cavities, outline of the phyllode as seen in transverse section, and disposition of the smaller vascular bundles. The first three of these characters are shown to be related to stickiness and the third and fourth to the relative humidity or aridity of the environment. The geographical distribution of sticky species in central and eastern Australia is determined. Sticky species occur throughout the region but are commoner in the more arid interior than in the more humid coastal regions. No relationship is apparent between stickiness and membership of the sections.