Diversity in Australian populations of Murraya paniculata (Rutaceae): New evidence from volatile leaf oils

Two entities are distinguished in Australian populations currently referred to as Murraya paniculata (L.) Jack. Both entities are allotypic in northern Australia. M. paniculata 'Small Leaves' occurs in much drier, largely deciduous microphyll vinethickets and is a sprawling shrub under 3 m in height with small (6–60 mm long, 540 mm wide) leaves, flowers and fruits on pedicels 3–7 mm long. It has a strongly aromatic odour to the foliage when crushed. M. paniculata 'Big Leaves' occurs in 'less dry' semideciduous notophyll vineforests and is a small tree 3–6 m in height with large (19–100 mm long, 12–50 rnm wide) leaves, flowers and fruits on pedicels 10–13 mm long. It has a less pungent odour to the foliage when crushed. The two entities differ quantitatively in volatile leaf oil composition with the 'Big Leaves' entity producing an oil approx. 1/5 the quantity of the 'Small Leaf' entity. Both germacrene-D and E-nerolidol are more prevalent in the 'Small Leaves' entity.