Chinese elm varieties

[shibui]

A number of different variations of Chinese elms have been selected and propagated. Each type has different characteristics we may like in our bonsai.
This thread is an attempt to identify some of the different types and their characteristics.
Feel free to add comments or pictures to enhance the topic.

Remember that any tree grown from seed is a new individual so it will not belong to any of the accepted varieties. Either give your seedlings a new variety name if they appear to be special or just refer to them as Chinese elm.

Corky Chinese elm. Sometimes labelled as Ulmus davidii or U. parvifolia 'Davidii'

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note that bark of younger corky Chinese elms can have far deeper furrows than this appears to have.
Leaves are generally lighter green. Main feature is the non shedding bark which builds up in dark, deeply fissured plates. Corky responds very well to all bonsai techniques and can produce dense foliage pads. Corky bark may rot at or below soil level if moisture is high leading to undesirable reverse taper. I've found that rubbing off most of the tick outer bark above the problem area rectifies the problem. In a couple of years mature bark will have formed again.

Catlin.
I believe that this is still a variety of Chinese elm but could be another species as growth and habit are quite different from mainstream U. parvifolias

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Catlin has darker green leaf colour than most other Chinese elms. It is more evergreen and holds the leaves right through winter unless it is very cold. New shoots tend to be very long and straight. Tends to produce fewer buds after pruning so ramification can be slow. Bark is smooth and flaking in leopard skin patches.

Nire Keyaki
Also known as Hokkaido elm. Believed to be a selection from far north of Japan. This is a true dwarf and only grows to around a metre tall.

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Nire Keyaki has tiny leaves with really short internodes which can make for great small bonsai. The downside is the branches are EXTREMELY fragile and snap off with even light bending. Best grown by clip and grow. Wire and bend at own risk. Bark is dark and deeply furrowed corky bark. tends to experience more die back than other varieties.

[shibui]

Seiju is a popular Chinese elm variety for bonsai.

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Seiju has quite small leaves that also reduce well in bonsai culture so is very suitable for smaller sized bonsai. Bark is corky. Wire and bend quite well.

Standard Chinese elm. I've seen others refer to 'reticulated' Chinese elm and assume that is the same type as this. Most street and park plantings are this type though many are probably seed grown.

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The main feature of these are bark is shed yearly leaving smoother bark with leopard skin patches of grey, brown and orange bark. Leaf is very similar in size, shape and colour to Corky variety. I find it difficult to distinguish between the 2 when plants are young. Eventually corky develops the characteristic thick, black bark while these have smoother, grey bark.

Seedlings
As mentioned above, every seed grown tree has a unique combination of genes so each will be slightly different. Seedlings from my seed source tend to grow a little differently to the above named varieties and generally have darker green leaves than the named varieties above. This particular individual one appears to ramify better than most.

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[Watto]

Very interesting post, thanks for the effort.

[Greg F]

Some nice trees there Neil with good trunks and excellent bark. The top tree looks great.
I appreciate the thread.
Matthew has some beautiful chinese elms too that would go well in this thread to.
I think im going to have to get me some corky bark elms, just when I thought I have enough trees.

Greg

[Phil Rabl]

You have set me thinking with this post, Neil, especially with the bit about corky bark varieties. I really like Ulmus and have 2 that I acquired as corky barks: (sorry about the photos being 90 degrees out of whack. I don't know how to fix that)

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This one is said to be Ulmus Parvifolia Suber.

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This one is said to be Ulmus sieju.

We used to have a different corky bark elm growing on our nature strip. I have always taken the term 'corky bark' to be a general descriptor referring to the bark rather than a species. I now want to dive into this a bit further. And your comment about seed-grown trees having their own unique set of genes has added to the intrigue for me. I hope others add to this string. There is definitely the makings of as newsletter article in what you have raised.

[Jarad]

Thanks Neil for creating this! You've got some excellent specimens there.

[shibui]

I believe that Ulmus parvifolia 'Suber' will be the same as the one I've posted as corky bark. Suber means corky plant tissue esp the bark of the cork oak. Like many cultivated plants they seem to get new common names as different people grow them.The 'Suber' Phil ahs posted looks very similar to my 'Corky' and is possibly the same clone.

Phil's Seiju does not look like the bark on any of my seiju elms. Mine definitely have dark, corky bark and develop it at just a few years old but it could be mine that are wrongly labelled. My Seiju also have much smaller leaves than other Chinese elms. It is the leaf that readily sets them apart among my elms.
This brings up another problem with plant names - mis-labelling. It is very easy for a new nursery employee to put the wrong labels on a batch of plants. Removable labels are often taken out by customers to look at then stuck back randomly into a nearby pot. In winter, without leaves, all the Chinese elm cuttings look similar so it is easy to mix up different types. Someone who is not familiar with the variety gets one then starts to propagate and we have many more mislabelled plants circulating.

Adding seedlings into the mix adds further complexity as some growers are determined to give their plants a variety name and just look at one or two characteristics of a named variety and try to match their seedlings so they can ascribe an existing varietal name

If you look closely at the bark type on street trees you can find a wide variation from smooth leopard patches through flaky bark right to deeply grooved corky type bark which shows the wide variation of types available from seedlings.

I'm hoping that others will also post photos of any named varieties they have to get a better look at the types available here. I know there is one called 'Frosty' which has a faint white variegation around the leaves but I have not had that variety for many years. Photos might and also show us how widespread mislabelling may be.

Regardless of the names, Chinese elms of all types are great for bonsai so don't get too fixated on the names. Just grow and enjoy them.

[Watto]

At the invitation of Shibui, here are a few of my Chinese Elm family.
The first is a Seiju that I purchased a few years ago from a bonsai nursery so I made an assumption that the naming was correct. It has very small leaves and corky bark.

[Watto]

Next is what I thought was the standard Chinese Elm, larger leaves and has the exfoliating bark.

[Watto]

This was purchased at a bonsai show somewhere and is what I call a corky bark. It too has small leaves and ...... corky bark.
It needs a lot of work and that will start in the next few weeks.

[Watto]

This one was dug at the secret Goulburn Bonsai Society Chinese elm dig site a few years ago, but unfortunately that site is no longer available to us as development has taken over.
This has very smooth bark and a leaf size about the same a Seiju elm leaf size so an interesting variation.

[MJL]

Thanks for starting this thread Neil and to others who are contributing wonderful photos and information. Yet another deep vein of knowledge being created on this forum. Very cool. Cheers, Mark

[jgmansell]

Beautiful trees and pots Watto, I am very envious!

john

[shibui]

Thanks for adding the extra photos Watto. The more the better to see the variety of types of Chinese elms available to us and what we can create with them.


A couple more photos from me that may help if you are trying to tell what you may have.

This is the variety I am calling 'Catlin' elm

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With characteristic smooth bark , dark green leaves and long, thin, straight new shoots.

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Also a side by side comparison of leaf from some varieties that may help others with ID.

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Left to right:
Corky nursery Chinese elm; Corky bonsai; Smooth bark bonsai; Seiju nursery plant; Seiju bonsai; Nire Keyaki nursey stock tree; Nire Keyaki bonsai; Seedling Chinese elm.

[Watto]

Thanks for the extra photos Shibui. The "Catlin" elm leaf extension looks just like the leaf extension I get on the elm I dug (so the unknown elm) so maybe it is a Catlin Elm. From now on I'll call it that until I know any better.