It's lucky Smoke Bush has gorgeous autumn colour and wispy fruit stalks,
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| American Smoke Tree in May, Melbourne Gardens |
... because its flowers are crap. Really. Small, dull and most irritatingly, hard to photograph. This is what they look like.
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| American Smoke Tree in October, Melbourne Gardens |
Flower parts are greenish and in fives, except for the single ovary in the middle of some flowers, and a yellow nectar disk. I gather flowers can be bisexual, male or female. Male flowers seem to be most common.
The American Smoke Tree, Cotinus obovatus, is one of two 'Smokebushes' commonly grown in cultivation. The other is the Common Smokebush, Cotinus coggygria. There are plenty of cultivars of the latter and a cross between the two species.
The American Smoke Tree, from southeast and central USA, has green (or blue-green) leaves for most of the year, but turning ('to die for') orange-red in autumn (see top of blog). New growth in spring is also colourful and pretty.
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| American Smoke Tree in October, Melbourne Gardens |
The Common Smokebush, on the other hand, can have deep claret-red or purple leaves for the entire year, equally a colour worth dying for (see end of post).
The smokiness comes from the finely branched structure that holds the flowers and then the fruits, sometimes described aptly as 'smoke-like plumes'. The effect is largely due to long silky hairs that extend out from the stalks of 'sterile' flowers, after flowering.
These hairy stalks are revealed as the flowering structure expands and some of the earliest flowers mature. In this next picture you can just see - if you squint - the purple hairs on unopened (presumably sterile or aborted flowers).
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| American Smoke Tree |
Things are a little clearer in the other species. Here on a piece of Common Smokebush from my local street where you can see the many purple hairs on the stalks of aborted/unopened flowers - all very small and even more unassuming than my featured species...
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| Common Smokebush |
[Since their flowering in August, I've been tracking the two specimens of American Smoke Tree on opposite sites of the path near Anderson Street, in Melbourne Gardens, and only one is developing lots of purple-haired, smoky plumes. In the other, the flowers are mostly dropping off and the stalks remaining hairless. So something else going on here...]
There are only two species of Cotinus, or sometimes two additional species found only in China. The genus is included in the family Anacardiaceae, which also includes the cashew (Anacardium), sumac (Rhus) and Pepper Tree (Schinus). These also have inconspicuous flowers.
In nature, American Smoke Tree is under threat of extinction from harvesting to extract a yellow or orange dye in the wood, although this was more common during the North American Civil War. The Common Smokebush is more secure, extending across large areas of southern Europe and through to northern China.
The American Smoke Tree should eventually grow into a small tree but our specimens are mostly still a little shrubby. Not quite as scrappy as the Common Smokebush but also not particularly elegant.
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| American Smoke Tree in October, Melbourne Gardens |
To to end, some pictures of the Common Smokebush, for comparison. First up, a plant growing in our home garden within Kew Gardens, London, back in 2012. A typically inelegant plant, as they often are, but always a colourful addition to our home garden (with Kew Palace looming behind). It's the red or purple leaved plant, leafless in winter.
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| Common Smokebush, London |
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| Common Smokebush, London |
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| Common Smokebush, London |
And finally, two images of the smoky plumes, on a specimen of Common Smokebush at the edge of Oak Lawn in Melbourne Gardens. Taken in mid-November 2020.
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| Common Smokebush, Melbourne |
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| Common Smokebush, Melbourne |
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