I suppose the greenhouses at Kew would contain a cinnamon tree (small, evergreen). The species with the spicy bark comes from India and Malaya but now I think grown commercially elsewhere in the tropics.
Most persimmons are Chinese-Japanese, but the one associated in verse with the 'possum (Opossum) is American, a tree that grows to 50 feet. Persimmons are grown in gardens in England, since most are temperate in climate preference.
The opossum in the American south is edible to some people but a nuisance to many. The true opossums are a New World group, but the name also is applied to some Australian relatives (relatives? I'm guessing).