South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent and with a total land area of 984 377 km² (380 070 sq mi), it is the fourth largest of Australia's states and territories. It is bordered to the west by Western Australia, to the north by the Northern Territory and Queensland, to the east by Queensland, New South Wales and Victoria, and along the south by the Great Australian Bight and the Southern Ocean. With 1.5 million people, the state comprises less than 10 per cent of the Australian population and ranks fifth in population among the states and territories. The majority of its people reside in the capital city Adelaide, with most of the remainder settled in fertile areas along the south-eastern coast and River Murray.
The state's origins were unique in Australia as a freely-settled, planned British province–all of Australia's other states were founded as convict colonies. Official settlement began on 28 December 1836 when the state was proclaimed at The Old Gum Tree by Governor Hindmarsh. The guiding principle behind settlement was that of systematic colonisation, a theory espoused by Edward Gibbon Wakefield that was later employed by New Zealand. The aim was to establish the province as a centre of civilisation for free immigrants, promising civil liberties and religious tolerance. Although its history is marked by economic hardship, South Australia has remained politically innovative and culturally vibrant. Today, the state is known as a state of festivals, and of fine wine.
The river's flora and fauna have been both deliberately and accidentally impacted since settlement. Native forests have been cleared, gravel removed for construction and many foreign species introduced. With construction of the linear parks, many species native to the river have been replanted and introduced species controlled as weeds. Since European settlement the river has been a frequently touted tourist attraction. It has also acted as the city’s primary water source, and main sewer leading to outbreaks of typhus and cholera.
Sturt's Desert Pea is an Australian plant in the genus Swainsona. One of Australia's best-known wildflowers, it is known for its distinctive blood-red leaf-like flowers, each with a bulbous black centre, or "boss". It is native to the arid regions of central and north-western Australia, and its range extends into all mainland Australian states with the exception of Victoria. It is the floral emblem of South Australia.