A New Framework for the Chamelaucium–Verticordia–Darwinia Group (Myrtaceae)

10 January, 2018

The story behind our latest project:  A New Framework for the Chamelaucium–Verticordia–Darwinia Group (Myrtaceae).

South-western Australia is home to a unique and diverse array of species belonging to the most horticulturally attractive plant groups in the country: the waxflowers, featherflowers and bells. Even beginner native gardners are familiar with the most commonly grown species such as Geraldton Wax, Yellow Morrison and Plumed Featherflower. However the full spectactular diversity of the group extends to about 300 species, currently housed in the genera Actinodium, Chamelaucium, Darwinia, Homoranthus, Pileanthus and Verticordia. These diverse plants all belong to the same group, subtribe Chamelauciinae of the family Myrtaceae. The majority of species are only found in south-western Australia, and are heavily represented in the Friends native plant sales, as well as the focus of a plant development programme by the Kings Park horticulture team.

In the last decade, the classification of these genera has been found to be inaccurate – a problem that really dates back to the early 1800’s. Research by Matt Barrett at Kings Park using DNA sequences and careful morphological comparison has revealed that Verticordia as currently considered is made up of many diverse groups, some of which are closer to other genera (Actinodium, Chamelaucium, Darwinia, Homoranthus and Pileanthus). The distinctive “featherflower” petals are actually misleading classification here, while other characters are more informative. A comprehensive review of these genera is long overdue, since the current classification misinforms breeding programs, taxonomic research, conservation, and research into pollination ecology and diversity patterns of the Australian flora. Although this will result in some upheaval of well-known names, it is time we put 200 years of confusion behind us to establish a firm classification for the future.

During 2018/2019 Matthew Barrett, a research scientist with Kings Park Science is going to undertake research on tribe Chamelaucieae. This project will resolve taxonomic issues in tribe Chamelaucieae, focussing on problematic generic delimitations and misclassified species in the Chamelaucium-Verticordia-Darwinia group of the family Myrtaceae. These aims will be achieved through an integrative taxonomic approach drawing on two decades of expertise by Dr. Barrett in the group, in collaboration with two other Myrtaceae experts, Dr. Barbara Rye at the Western Australian Herbarium and Dr. Peter Wilson at the Royal Botanic Gardens Sydney