This is the monkey brain I brought back to our kitchen. There were plenty more at the base of the Osage Orange tree in a small park near the Yarra River, not far from home in Hawthorn. The stalk is a clue to its real identity. And perhaps its colour, texture and location.
It's autumn and this tree is for turning, to butcher and paraphrase the most famous quote of a recently dead British Prime Minister. The crown of the tree is half yellow and half green, and the yellow leaves are just starting to joining the monkey brains on the ground.
Osage Orange (Maclura pomifera) evolved near the Red River valley of southern Oklahoma and northern Texas, an area also devoid of monkeys I believe. It was used for hedges on the Great Plains and then spread from there to become a quite commonly naturalised plant in North America.
John Pickard, a botanist who used to work at the Royal Botanic Gardens in Sydney prepared a 28 pages Conservation Management Report on an Osage Orange hedge at Muogamarra Nature Reserve north of Sydney. He says that Osage Orange was 'the favoured hedge plant in the prairie States of the United States before the invention of barbed wire in 1874'. The Osage has thorns...
Osage Orange has also become naturalised in Australia (see Atlas of Living Australia), particularly in New South Wales, but you don't see it planted much these days - although any botanic garden worth its salt has one or two. It's very much an old fashioned plant like the Pepper or Peppercorn Tree (Schinus molle). John Pickard doesn't consider the hedge at Muogamarra to be any threat to the nearby bushland.
As to its common name, the Osage were a local tribe in the Red River valley. And while the fruit looks more like the brain of a monkey (apparently) than an orange, it does smell like a citrus fruit. The Great Plains Nature Center (source of my North American information) suggest you find one that has been out in the sun for a while and enjoy the orange-peel-like perfume of the skin. Like ginkgos, and plenty of other plants, the trees are either male or female so not all will bear fruit.
Osage Orange is in the Moraceae and the fruit does look like a pumped up mulberry, another member of this family. However the fruit doesn't look like something you'd eat, at least to me. If you split it open it's full of (up to 200) seeds and other bits and pieces of not particularly attractive plant material. Apparently the seeds are edible but you have to remove them from the pulp and skin which you should definitely not eat.
As you might have gathered by now, Monkey Brain is one of its other common names, along with Hedge Apple and Bodark. The name Bodark is a corruption of 'bois d'arc', French for bow wood. The branches were once used to make bows for hunting by the Osage and other Native Americans.
You are unlikely to find Monkey Brains in the kitchens of North America but you may find them under beds and lining basement windows. It's thought that they will frighten off spiders and cockroaches. As it turns out the fruit contains a chemical called elemol which does deter certain insects. I see the mosquito in that list so I may leave my Monkey Brain here in the kitchen until summer.