This tree is found in the Adelaide Botanic Gardens, near the Main Gate on North Terrace. It is known as Sweet Bursaria, Australian Blackthorn, Mock Orange, Native Box, or SA Christmas Bush. The botanical name is Bursaria spinosa (Syn. Cyrilla spinosa)
Bursaria comes from the Latin bursa, meaning purse; spinosa also Latin, means spiny or thorny. It is placed in the Pittosporum family. It is native to the southern parts of Australia, and an aggressive coloniser of disturbed ground. An evergreen, it is unpopular in cultivation because of its prickles. It can grow to a height of 12 metres and live up to 60 years old.
It finds a place among our Treasured Trees because it is an outstanding specimen of its kind, and a remnant of what was local vegetation. It is rare now, in Adelaide, and it is very old, and may predate the formation of the gardens in the 1850s. It is considered to be of regional importance for its age and rarity.