Are Arbutus and Castanospermum both native to Australia?
no
Castanospermum
Castanospermum australe (Moreton Bay Chestnut or Blackbean), the only species in the genus Castanospermum, is a flowering plant in the family Fabaceae, native to the east coast of Australia in Queensland and New South Wales, and to the Pacific islands of Vanuatu, New Caledonia, and the island of New Britain (Papua New Guinea).
 Members of this genus accumulate iminosugars in their leaves.
Arbutus
Arbutus is a genus of 11 accepted species of flowering plants in the family Ericaceae, native to warm temperate regions of the Mediterranean, western Europe, the Canary Islands (Teneriffa) and North America.
 The name "Arbutus" was taken from Latin, where it referred to "A. unedo".
Arbutus andrachne
Arbutus andrachne, commonly called the Greek strawberry tree, is an evergreen shrub or small tree in the family Ericaceae, native to the Mediterranean region, the Middle East, and southwestern Asia. Arbutus xalapensis
Arbutus xalapensis, commonly known as the Texas madrone, naked Indian tree or Texas madroño, is a species of flowering plant in the heather family.
 It is native to Central America, the southwestern United States (western Texas and New Mexico), and throughout Mexico.
 It is found in canyons and mountains, on rocky plains, and in oak woodlands, at altitudes of up to 3,000 m (10,000 feet) in the south of the range, but lower, down to 600 m (1800 feet) in the north of the range. Arbutus unedo
Arbutus unedo (strawberry tree) is an evergreen shrub or small tree in the family Ericaceae, native to the Mediterranean region and western Europe north to western France and Ireland.
 Due to its presence in southwest and northwest Ireland, it is known as either "Irish strawberry tree", or cain or cane apple (from the Gaelic name for the tree, "caithne"), or sometimes "Killarney strawberry tree". Strawberry tree
Strawberry tree is a common name for "Arbutus unedo", a tree with edible fruits, native to western Europe and the Mediterranean basin, and cultivated in other temperate areas Cryptandra arbutiflora
Cryptandra arbutiflora, commonly known as waxy cryptandra, is a shrub species in the Buckthorn family, Rhamnaceae.
 It is endemic to the south-west of Western Australia, occurring between the south coast and the Dandaragan area to the north and also near Geraldton.
 It ranges from 0.05 to 1 metre in height and produces cream bell-shaped flowers between May and November.
 The species was first formally described by botanist Eduard Fenzl based on plant material collected by Charles von Hügel from the Swan River area.
 Fenzl's description was published in 1837 in "Enumeratio plantarum quas in Novae Hollandiae ora austro-occidentali ad fluvium Cygnorum et in sinu Regis Georgii collegit Carolus Liber Baro de Hügel" The Latin specific epithet "arbutiflora" alludes to the flowers which are reminiscent of those of "Arbutus unedo", the Irish Strawberry Tree. Arbutus menziesii
Arbutus menziesii (Pacific madrona, madrone or arbutus) is a species of tree in the family Ericaceae, native to the western coastal areas of North America, from British Columbia to California. Mystic Vale
Mystic Vale is a forested ravine that was acquired by the University of Victoria in 1993 and is located outside the ring road to the southeast of campus.
 Its tree canopy is dominated by large specimens of Douglas-fir and grand fir.
 A few western red cedar also occur.
 Scattered among these conifers are deciduous trees such as bigleaf maple, black cottonwood, and willow.
 Some Garry oak is present at the forest edge.
 Canada's only native broadleaf evergreen tree, the arbutus, is also present. Arbutus arizonica
Arbutus arizonica, commonly known as Arizona madrone, is a tree species in the heath family that is native to the southwestern United States and northwestern Mexico.
 Its range extends along the Sierra Madre Occidental cordillera from the Madrean Sky Islands of southeastern Arizona and southwestern New Mexico south as far as Jalisco.
 It has been found in Sonora, Chihuahua, Durango, and Sinaloa, with one isolated population in Tamaulipas.