Kunzea ambigua is a small- to medium-sized spreading shrub that may reach both in height and width, though is usually much smaller. Its bark is fibrous and furrowed, while the narrow lanceolate green leaves are 0.5–1.3 cm in length and 0.2 cm wide, with hairy new growth. Occurring from September to December or January, the white flowers are 1.2 cm in diameter and sweetly fragrant. The stamens are longer than the petals. The flowers are followed by small woody capsules 0.4 cm in diameter.
Taxonomy and naming
Kunzea ambigua was first formally described in 1797 by James Edward Smith who gave it the name Leptospermum ambiguum. English botanist George Claridge Druce gave it its current binomial name in 1917. The generic name honours German naturalist Gustav Kunze, while the specific epithet is derived from the Latin adjective ambiguus meaning "doubtful" or "uncertain". Its common names are white kunzea and tick bush. A pale pink-flowered hybrid with Kunzea capitata has been recorded from Stony Range Flora reserve in Dee Why in Sydney's northern beaches region.
Distribution and habitat
Kunzea ambigua is found from northeastern New South Wales, having been recorded in the Grand High Tops of the Warrumbungle National Park, through Victoria and into Tasmania. It grows on sandy soils in coastal or near-coastal regions. It is a very common dry forest shrub of the Sydney region, and regenerates in disturbed or cleared areas. It is associated with scrub she-oak, Melaleuca nodosa, cheese tree in heath or scrub, and with red bloodwood, peppermint gum, forest red gum, woolybutt, thin-leaved stringybark , and white feather honeymyrtle in forested areas. In Wilsons Promontory in Victoria, Kunzea ambigua is the dominant species within scattered areas of treeless heath that occur on granite hills and mountains. In recent times, it has been discovered that the Kunzea ambigua plant grows abundantly in Flinders Island and North East Tasmania. Tasmania regularly experiences strong westerly winds and a high annual rainfall of over 700mm. This harsh, windy and brisk climate is the ideal environment for the Kunzea ambigua plant to thrive. In particular, this wind has played a key role in blanketing Flinders Island and many parts of Tasmania with Kunzea seed and thus it grows profusely throughout the island.
Ecology
Insects are the main pollinators of Kunzea ambigua; these include various types of beetles including jewel beetles, scarab beetles, flower beetles, and checkered beetles as well as butterflies, flies, bees and wasps. The tick bush is killed by fire and regenerates from seed. Plants can also colonise unburnt sites with ample sunlight.
Use in horticulture
It was one of the first species of Australian plant introduced into cultivation in England. It is a hardy and adaptable plant that is used in windbreaks and sand dune stabilization plantings, as well as gardens, particularly in Australian gardens using native plants according to principles of natural landscaping. The species attracts Australian native insects, and can provide shelter for small birds and the long-nosed bandicoot. It can regenerate quickly after disturbance, suggesting it may have weedy potential if planted outside its natural range.
Therapeutic benefits
Kunzea ambigua was traditionally used by Australian Aboriginal communities to relieve irritated skin, muscle tightness and pain. Kunzea essential oil is now registered with the Australian Therapeutic Goods Administration as providing temporary relief of the pain of arthritis. Kunzea ambigua has since been used as the active ingredient in topical products for relieving muscles, joints and inflammation. The first known product to use Kunzea essential oil was listed with the TGA on the 13 Jul 2017 for the following approved therapeutic claims:
May help enhance/improve/promote/increase joint mobility in mild arthritis
