
Persian Silk Tree (Albizia julibrissin)
Dear Readers, I was so taken with this tree that I spotted during my visit to Dulwich at the weekend that I thought I’d find out a bit more about it. The plant was originally imported to Europe from the Caspian Hyrcanian Forest in Iran by Florentine nobleman Filippo degli Albizzi, who gave the genus its Latin name. This area of forest is also home to several other rare London street trees, such as the Caucasian Wingnut and the Persian Ironwood. Persian Silk Tree is also native to the area east from Azerbaijan through to China and Korea.
In the UK this is still a rare and unusual street tree, but in ‘London’s Street Trees’ Paul Wood speculates that, like Buddleia, this is a tree that could ‘jump over the fence’ and become a pest, as it has in the US, where it’s a ‘weed of concern’. But for now, this is a truly stunning tree when in flower. Furthermore, the leaves close when it rains (hah!) or as night falls. When we were growing up we had a ‘sensitive plant’, which would collapse if it was touched, which happened rather too often for the poor thing. In the end it gave up doing anything at all, as if on strike. I suspect it was a member of of this or a related plant family.
To celebrate this habit of the Persian Silk tree, its Persian name means ‘night sleeper’, while the Japanese name means ‘sleeping tree’.

Silk tree by day and night (Photo By Abubiju – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=49213798)
Pretty as it is, the Persian Silk Tree is not loved by everybody: a North Carolina plant website describes it as ‘aggressive, high-maintenance and short-lived’. In the States, the suggestion is to plant sterile cultivars, such as ‘Summer Chocolate’. There are no such problems here, yet, but as the climate changes all bets are off. The flowers are popular with insect pollinators and some birds, and some butterflies, such as the Three-spot Grass Yellow shown below, use it as a food plant for their caterpillars.

Three-Spot Grass Yellow laying its eggs on Persian Silk Tree (Photo By © 2010 Jee & Rani Nature Photography (License: CC BY-SA 4.0), CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=18449483)

‘Summer Chocolate’ Persian Silk Tree, Virginia, USA (Photo Famartin, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
The flowers and bark of the tree are used in Traditional Chinese Medicine as a mood booster and nerve tonic. Seeing the tree in Dulwich certainly cheered me up, it’s such a show stopper. Who would have guessed that this plant is a member of the bean family (Fabaceae)? Well, I guess I would have done once I’d seen the pods.

The wood of the Persian Silk Tree is light but not particularly durable, according to The Wood Database, so it’s normally used for small craft and art projects.

Persian Silk Wood (Photo from https://www.wood-database.com/mimosa/)
In spite of its beany heritage, the seeds of the Persian Silk Tree are poisonous, so having them on toast is a no-no. The young leaves are said to be edible boiled, but honestly, haven’t the leaves got enough to do, what with drooping every night and reviving every morning? Maybe stick to the spinach 🙂
In Chinese folklore, the Persian Silk Tree’s name is translated as ‘ joy of togetherness’ – the story goes that a devoted Chinese queen searched endlessly for her husband, a fallen Emperor – when she couldn’t find him, she died of a broken heart, but the two of them are fused together forever in the flowers of the tree.
I also loved this touching story from Mandana Boushee. Her mother died in January 2018 in Iran, mine in December 2018 in Dorset, and yet the words she’s written could apply to my mother too.

Photo by Steve Guttman at https://www.flickr.com/photos/steveguttman/2769514474
Confusingly, the Persian Silk Tree is also known as Mimosa, though to me, Mimosa is this yellow-flowered plant. There’s no doubt about which plant is referred to in this poem, though, by American poet Kathe L. Palka. I love how closely observed it is, and the sense of sadness that I share when a tree is dying. See what you think.
Mimosa in the Yard
by
Kathe L. Palka
At thirty feet,
testament to the first owner’s
exotic tastes,
it died this year,
trunk cracked and bug infested.
A few limbs leafed out
in late spring, withered yellow
then bare by mid July.
In its prime it offered shade well placed,
I’d watch
the boys play in its cool
embrace as I cooked meals.
Yet,
it’s not the respite from the sun,
the pink fuzz of summer
alive with butterflies
or
the seed pods shaken
like maracas in October
that I’ll miss,
but the way the leaves closed up
each night at sunset before it slept.




























