Actinostrobus

Common names include cypress, sandplain-cypress and cypress-pine, the last of these shared by the closely related genus Callitris.

There are three species in the genus, all endemic to southwestern Western Australia: A. acuminatus Parlatore A. arenarius Gardner A. pyramidalis Miquel A 2010 study of Actinostrobus and Callitris has placed all three species of Actinostrobus within an expanded Callitris based on analysis of 42 morphological and anatomical characters.

The female cones start out similarly inconspicuous, maturing in eighteen to twenty months to 10–20 mm (0.39–0.79 in) long and wide, globular to acute-ovoid, with six thick, woody scales, arranged in two whorls of three, and a further nine to fifteen thin, sterile basal scales.

The cones remain closed on the trees for many years, opening only after being scorched by a bushfire; this then releases the seeds to grow on the newly cleared burnt ground.

The closest relative of Actinostrobus is Callitris, which is much more widespread, occurring in most of Australia, and differs in its cones lacking the basal whorls of small sterile scales.