h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I don't think my unknown tree is a mimosa. It has never had any blossom or any berries. It is a deciduous tree and the bark is very smooth. Paul were you able to see the photo of my tree on Flickr?

My unknown tree does not have any odour.

I could see it clearly and enlarge it.

Odor is primarily an issue on hot summer days when its actively flowering, rather sweaty odor.

Mostly smooth, white bark is part of the profile.

It has a slightly green tinge to the bark more like a very pale olive colour. There were no flowers throughout the spring like my other tree. There has been no odour coming from the tree even on the hottest of days.

Afterthought, Rosa, on your tree of heaven: it may not be flowering on account of too little hot weather.

The UK is probably very close to the northern limit of its range.

It probably does push up occasional off shoots from tuberosities on its roots.

These can be dug up, separated from the parent tree and potted or transplanted, given copious water the first few days.

This year it has been very hot this year in the UK, particularly in the South East of England. There have been most days 32+ Celsius during our heatwave where temperatures starting to rise in May. It has only been recently that the temperatures have gone back to seasonal normal.

I'm accustomed to that tree in southern California conditions, with summertime daytime temperatures typically between 90F/32C to 100F/38C and not infrequently higher.

In the tropical desert where I am now with daytime summer temps typically between 110F/43C to 122F/50C and sometimes higher, its too hot for the tree of heaven.

More trivia, the tree of heaven has long, compound leaves or fronds with an indefinite number of papery lanceolate leaflets attached to a stiffer petiole, from which the leaflets separate when the leaves fall, the petioles falling separately.

Rosa, does it have clusters of seeds that resemble maple seeds?

No, it does not have any seeds of any type. It only has broad flat leaves and they are pinnately compound leaves. The bark is a light olive and it is very smooth but they are the occasional knots. It is a slow grower.

I've looked again and I'm completely sure.

Ailanthus Altissima, the tree of heaven.

Looks just like the ones I planted for my Mom.

The bark changes color when wet.

When thoroughly dry, its whiter.

The lanceolate leaflets separate from the petioles of the pinnately compound leaves and fall separately from the petioles during the autumn leaf fall?

I think the differences between your description and mine are due to differences of climate.

My tree never produces any flowers. I cannot remember what happens to the leaves in autumn.

It is, whatever else, quite a nice tree.

I pulled up four of them today -- seedlings that were growing a mile a minute.

I found a few very fine seed pods and I have looked at pictures of the honey locust tree and my resembles. When I moved into the flat in South Ockendon in May of 2004, the tree was still small as it is a slow growing tree. This is the first time the tree has produced any pods. The other tree next to it has just appeared in the past three to four years and has only recently bore white blossom.

With the honey locust or carob tree, the seed pods are very robust, sweet, bean pods that taste like chocolate.

The pod is eaten, the beans are oval shaped and impossibly hard.

With the tree of heaven, the seed pods are thin and papery, bitter, sour and puckery with tannic acid and are not eaten.

For some reason, environmentalists in my area are at war with black locusts. But honey locusts which resemble them, are fine.

Il ike the blossoms and the pods, but the thorns are painful if you step on them with your bare feet.

Honey locusts lack thorns.

Black locusts are viciously thorned.

" The native species of honey-locust has large thorns on its stems and bark"

You may be thinking of a version that was bred to lack the thorns
http://www.mortonarb.org/trees-plants/tree-plant-descriptions/thornless-honey-locust

Reset my AC to 84F/29C last night.

Its getting cooler, with thunderheads to the west over the Santa Rosa Mts. and Palm Springs with flash flood warnings in the Santa Rosas, The San Gorgonio pass and Mt. San Gorgonio.

It is a big mystery on why it has taken so long for the pods to appear and why the tree never bears any blossom.