Baeckea imbricata [Myrtaceae]; Heath MyrtleWhen first exploring Sydney’s bushland after relocating from New Zealand I was drawn to heath vegetation. There is an incredible diversity of species and of flowers, and the crowded compositions were exciting to a plant enthusiast with an inordinate fondness for small-leaved, wind-shorn shrubs. (It took me a little longer to fall in love with the open, dry, ‘scrappy’, ‘monotonous’ forests and woodlands, although it did very much happen).
In ‘coastal headland cliffline scrub’ communities – the heaths that occupy the sandstone platforms of coastal Sydney – one of the first plants I was intrigued by was hard to identify, due to the aesthetic similarity of so many of the plants in this environment. In an effort of convergent evolution, many plants here evolve a similar appearance, with reduced leaves (to minimise transpiration), mounding form (as a response to – and result of – wind exposure) and upright branching structure. On the third or fourth visit I finally saw one in flower and was able to confirm that it was indeed Baeckea imbricata, a member of the myrtle family, Myrtaceae, to which eucalypts, paperbarks and many other Australian plant species belong.
While not a particularly flamboyant plant, it is beautiful in its subtlety. Its stems arch upwards, animated. The tiny circular leaves hug the plant and are arranged in a regular, repeating pattern that is quite gratifying, especially when contrasted with larger-leaved heathland species such as Correa alba (as seen above).
I believe this plant to have immense horticultural potential, as it could replace dense exotic shrubs such as Buxus microphylla and Nandina domestica, species that are commonly used in street plantings, and which have little or no demonstrated ecological value in Sydney, not to mention any relation to their natural context. Through my own experiments I’ve found that despite it only growing naturally in thin, infertile sandy soil on water-retentive platforms it could be used in many garden plantings, provided it grows in situations that simulate the subsoil presence of moisture provided by the sandstone bedrock, such as being planted adjacent to paving and masonry walls, or above slabs or footings. Like many in the Myrtaceae family, it appears to tolerate a range of soil types – rather it is soil moisture and substrate that are critical. One issue for this plant is that healthy plants can sometimes defoliate from the base as they grow, creating an unattractive basal zone. We are exploring ways to solve this, such as hard biannual pruning or planting design strategies that render it unimportant.
