The first of our two Coffs Harbour Davidson’s Plum trees has bourne its first harvest – over a kilo so far and at least a couple more kilos to go. They bear so prolifically that a couple of trees is probably all I need, but I’m tempted to propagate more from these seeds anyway, and find somewhere somewhere (?) to put them.
Davidson’s plums make the best jam, so good that they make a supurb gift. It’s the only jam I really bother with these days – mostly I go for not-jams instead. They also make a very good sauce and cordial, and I’ve heard wine too. I’ve propagated and planted scores of seedlings in the riparian rainforest of our rural home. So it’s very exciting (and a bit homesick inducing) to have this three year old tree fruiting here.
I had discovered when writing the earlier posts that Davidson’s Plums are full of good stuff – antioxidants, potassium, lutein, vitamin E, folate, zinc, magnesium, calcium – but I hadn’t realised just how rich they are in compounds that are so ‘nutraceutical’ that they deserve a place in this Garden Pharmacy series.
The big claim to medicinal fame is a compound called ‘anthocyanin’, which it the thing that gives purple coloured fruits and vegetables their distinctive colouring. Anthocyanins are renouned for their health benefits. They’re what give blueberries and acai their reputation as superfoods. But here’s the thing: Davidson’s Plums have over double the anthocyanins of acai and nearly three times the anthocyanins of blueberries.
Anthocyanins do a number of generally healthy things like being anti-oxidant, anti-inflammatory, neuroprotective, liver and kidney protective, decreasing bone loss, improving cardiovascular health.
But the one that really interested me was the way they improve gut microbiota and the effect that has on mental health, and on osteoarthritis, and on obesity, all of which are possibly, probably connected with the gut microbiome. Anthocyanins give a competitive advantage to “good” gut microbiota such as Bifidobacteria spp. and Lactobacillus-Enterococcus sp over “bad” gut microbiota. I’m thinking that Davidson’s plums could be a good garden medicinal for resetting the gut microbiome to a healthy state after an illness or antibiotic (plant or pill).
It does appear though that the anthocyanins may not survive jam or sauce making – they aren’t stable when heated. So maybe half for jam making, and half for eating fresh or freezing for medicinal use. I’ve been eating these when they are soft and ripe with yoghurt, just split open to remove the seeds and sprinkled with sugar, not because I need it medicinally but just because they’re very delicious.
Davidsonia jerseyana, Family Cunoniaceae, Davidson’s Plum
There are three species of Davidson’s plum, but D. jerseyana is the one we have. D. pruriens is native to far north Queensland where it grows to over 10 metres tall. Further south it gets to 5 or 6 metres tall with no branches and a mop of foliage on top, making it good for narrow spaces so long as there are no overhead wires. D. johnsonii can also get that tall but it is branched and bushy, and rare.
D. jerseyana is a small tree (2 to 5 metres), and like D. pruriens it doesn’t branch which makes it suitable for narrow spaces. It’s an attractive tree with red new growth, but the leaves have fine hairs that are irritant so you need to put it somewhere where you won’t be brushing past it all the time. It’s native to southern Queensland and northern NSW rainforests, so think rainforest conditions – dappled shade, plenty of water, protection from wind and frost.
The fruit is ripe when it’s deep purple. It falls from the tree while it’s still hard and needs another week or so to soften before eating or cooking. It’s very tart. I’m not much of a sweet tooth but even I need a sprinkle of sugar to enjoy it.
Most of the references I found by following references from this link: Anthocyanins in Chronic Diseases: The Power of Purple https://pubmed.ncbi.nlm.nih.gov/35631301/
You will find the rest of this series by clicking the tag Medicinals.
Acknowledging debt to First Nations Australians for knowledge of the value of this plant.
The first time I tasted this fruit was as a sorbet. As well as being the most delicious flavour, the colour was an astonishing magenta, very memorable! My oldest D. jerseyana is nearly 5 m and still growing. Since having a resident possum I get little fruit, not because they eat it, but because they knock off the green fruit while climbing the trunk. Since the common technique of wrapping the trunk won’t work, I’m still trying to figure out how to stop the damage, suggestions welcome.
I should freeze some for sorbet. It’s such a dinner party surprise treat. But I can’t think what to do about your possum. Wildlife is so hard to deal with. Tiny creatures like aphids I can cope with fine – I just encourage another creature tha eats them. But big creatures are hard to deal with. I’ve heard of people successfully using a disk around the trunk of a tree about 1.7 metres up, and/or a sheet of laserlight around the trunk to defeat a possum. But this is a good story about how determined they can be. https://anpsa.org.au/APOL2007/may07-1.html
Linda, I remember reading this when I went looking for solutions. The tree is planted so I can reach the fruit from the upstairs verandah, which unfortunately makes it also a highly desirable possum shortcut to that roof. I don’t expect to be able to stop them accessing the roof as there are other trees around, I just want to limit the damage being done to the Davo’s trunk. I’ve seen the plastic trunk sleeve used in a park in town, but thought it would interfere with the fruiting. I wonder if it would still baffle a possum if I spaced it out away from the trunk? Hmm. Will let you know how that works.
Thank you for all the D. Jerseyans aka Gudjin recipes. I have two trees which fruited prolifically last year and now I know what to do with the fruit. And what to call it. The genus needs renaming.