Phylogeny reconstruction of Callitris Vent. (Cupressaceae) and its allies leads to inclusion of Actinostrobus within Callitris

Relationships between Callitris, Actinostrobus and Neocallitropsis, members of the southern hemisphere 'callitroid clade' (Callitroideae sensu Gadek et al. 2000) of Cupressaceae, are estimated using a database of 42 morphological and anatomical characters. Callitris is paraphyletic, with Actinostrobus being closer to a large well supported clade of 15 Australian species of Callitris than are C. baileyi, C. macleayana and the New Caledonian taxa. The New Caledonian unispecific endemic, Neocallitropsis, is sister to the clade comprising all Callitris and Actinostrobus species. There are marked differences between this estimate of the phylogeny and two recent estimates based on nuclear encoded DNA sequence data and non-molecular data, respectively, but some simlarities to the molecular estimate are highlighted and lead us here to formally include Actinostrobus within Callitris. Further molecular data are needed to test these results and explore the cause of the conflict between these estimates of the phylogeny within the group, and the status of Neocallitropsis.