Brisbaneで最も古い樹木はどれですか。
The oldest tree in Brisbane is the Macadamia Nut Tree in the City Botanic Gardens, at the southern end of the rainforest section near Alice Street. Walter Hill, the gardens' first curator, began trialling the nut here in 1858 using seed brought from Gympie, and the tree that grew from those trials is still standing: roughly 165 years old, 17 metres tall, a metre through the trunk. The National Trust of Australia's significant tree database and a State Library of Queensland account independently record it as the first macadamia brought into cultivation anywhere, and popular sources go further, calling it the oldest cultivated macadamia alive and the starting point of a crop now grown commercially across four continents. That wider claim rests on secondary sources rather than the two-source bar this page applies to age itself, but nothing found contradicts it. The next oldest tree here is close behind: Prince Albert's Cook Pine, planted in 1868 and now the tallest tree in the gardens at 45 metres, though its estimated age band (roughly 158 years) sits below the macadamia's.
This page draws on the National Trust of Australia's Significant Tree Database and, for several entries, the State Library of Queensland, both describing work under Walter Hill, the City Botanic Gardens' first curator from 1855. Thirteen of the 20 trees here stand inside that garden; one more, the Eagle Street Fig Trees, is a kilometre north on a traffic island, planted in 1889. Three stand three kilometres upriver in Newstead Park, led by the Talking Tree, which predates Newstead House beside it. One, a memorial crow's ash in Toowong, was planted in September 1924 by a council abolished the next year, one stands on a Milton street corner, and the furthest out, a Bunya pine, marks a farm and cannery site in Manly West, 14km from the centre. Most of the 20 carry only one directly-verified source, so their planting dates are that source's account rather than independently corroborated, and the page says so on each. The Macadamia Nut Tree's 1858 date comes from when Hill's trials began rather than a single measured planting day, which is why its age is a band. See the full list of 20 on the Brisbane page.