[JTh]

Could any of you help me with the identification of another yellow-flowered tree? This  one (there were several of them) was seen outside Agia Sofia in Thessaloniki some days ago? OOne of them also had large triangular fruits (I gathered a few). The photos were taken with my mobile phone camera and it was very windy, so they are not very sharp

[Fleur Pavlidis]

This is the lovely Koelreuteria paniculata which I photographed for the autumn colour thread here.

[John]

There are some very large specimens near us here in SW London in a cemetery. Though due to the lack of warmth over the last year they have failed to flower. This was mentioned on out UK branch visit to Hilliers Arboretum where a smaller specimen outside the visitor centre had failed to flower and Dave Jewell pointed this out to us.

[Alisdair]

If you click on the blue Home tab, then put Koelreuteria in the search box on the right, you'll find quite a few useful references to this splendidly useful and utterly drought-tolerant tree, aptly known as the Golden Rain Tree, elsewhere in the forum.
As John says it does need a hot summer to flower well, but this is really only a problem in northern Europe, and never in mediterranean conditions. W J Bean of Bean's Trees and Shrubs said that the finest specimens he'd seen in Europe were in central France.

[David Bracey]

Very easy to grow from seed .  Within a few years it is a small tree.

[JTh]

Thank you all of you for identifying this tree,  sounds like something worth looking for.  The flowers were beautiful and the seed capsules very interesting, I hope I'll have some luck with the seeds I gathered, I'm  not quite sure they were ripe  enough.

[MikeHardman]

To add a bit of context...

There are just three species of Koelreuteria, identifiable by their leaves:
- evergreen  (and bipinnate) --> K. elegans
- deciduous:
  - unipinnate --> K. paniculata var. paniculata
  - commonly and largely bipinnate --> K. paniculata var. apiculata
  - consistently and fully bipinnate --> K. bipinnata

The odd/even-ness of the pinnation can also give a clue:
- K. elegans - odd pinnation (rachis ends in single leaflet)
- K. paniculata - odd or even pinnation
- K. bipinnata - even pinnation (rachis ends in pair of leaflets)

There are various ssp. and cultivars, including a fastigiate form of K. p.
Just to confirm, it looks like yours, Jorun, is indeed K. paniculata var. paniculata.

[JTh]

Thank you, Mike. I have never seen it for sale around here, so I guess I'll try to start propagating one from seed.