unfortunately without a picture, any kind of definitive i.d. will be likely very difficult---that said, you might check out crinodendron hookerianum.

George is probably right, that's the only Chinese Lantern looking tree to my knowledge. So ungrowable in zn 4, it's not even funny.

Actually, it could also be Abutilon. I have never seen a crinodendron in bloom myself in the UK, though I have no doubt they are cultivated there and it is quite believable that that is what you saw. However, Abutilons of all colors seemed rather widespread and memorable in SE UK gardens and I would hazard a guess that they are much more common than Crinodendrons. Some people find their flowers have a Chinese lantern shape as well.
Also rated zn 8 btw, though would be more amenable to pot culture in continental climate parts of the US than Crinodendron, which can tolerate neither warm summers or cold winters.

This post was edited by davidrt28 on Wed, Jun 25, 14 at 7:25

David, you might be right about the ablution or it might be a crinodendron (not uncommon in "keen" gardeners' gardens in the u.k.), or maybe something else (a tomatillo/huxk tomato for example?????----again, without pictures and with only a "chinese lantern" description we are probably both still essentially guessing as to what the o.p. really saw, sad to say.

No orange in the Chilean lantern tree flower color, whereas many flowering maples are orange.

I immediately thought of Crinodendron hoohkerianum.

But when you say 'evergreen' do you mean a broad leaf or a conifer. Is it possible you saw a conifer with Tropaeolum speciosum growing through it? That is quite a common combo.

Tomatillo/tomato is very unlikely unless it was in a vegetable garden.

I don't know of any hardy red or orange Abutilons so unless it was in a pot I doubt that's what it was.

There are shrub/small tree form Abutilons hardy in the U.K.

For instance.

Yes, there are but not any fully hardy red/orange ones that I know of. Kentish Belle is only hardy in sheltered spots in the South, especially along the coast and in conurbations. It can only take a light frost.

The RHS link gives hardiness zone H3 - Hardy in coastal and relatively mild parts of the UK (-5 to 1)

Perhaps the OP could come back and give us some more details - like what time of year was this? Was it in the woodland or the formal gardens? Pot or open ground?

The OP's plant might have been KB although I wouldn't describe it as looking like an evergreen or being a tree.

Flora, I'm certainly not as informed as you are...after all I don't live there...but I'm sure on a visit to London in the 1990s (I went 3 times, early, middle, late 90s, roughly a week each) I saw orangey-or-red abutilons planted, in the ground, in central London. More than once. One I remember quite vividly was near St. Pauls...IIRC there's a square called something like "Pasternoster" that had a hexagonal office building. In front of it there was a large planting bed planted in the full tropicalesque style, including a fairly big Canary Island date palm, and such an abutilon, and a bunch of cannas and other showy things. Recent google images show this bed to be completely barren :-(

You'd think in an era of cheap digital cameras, the OP might have taken a snap of it! I remember during my trip to the UK (& Europe) in the 1990s, agonizing about using up expensive film shots on gardens or rare plants. The video camera was helpful but I didn't lug it on the 2nd and 3rd trips.

Maybe with more info from OP you can Google earth the sight in London where the "tree" is located. I am unsure just how close you can get on Google earth, though. Enough to see the plant ? Likely that is too near for Google? Maybe enough for Floral or anyone on here in the UK to eventually find out more info. Maybe someone is near London, or knows someone who is.

You are thinking of street view, not google earth. (though they might be fully integrated now, for all I know) You would never get the resolution to ID a flower from a satellite photo. (maybe the US military can, not us!)

davidrt28, the key words there are 'in central London'. I mentioned large conurbations as a warmer climate where Abutilons might grow outside. They also survived where I grew up on the South Coast about 1/2 mile from the sea. But they will only thrive in favoured micro climates, not as a general rule.

The other thing to remember is that if you went to London in the Summer you might well have seen Summer bedding i.e. plants put out only for the Summer and replaced by other material for winter. Cannas, for example , are frequently used in summer bedding schemes to get a tropicalesque feel. Canary Island Date Palms are being increasingly seen as the climate warms up but still only in warmer micro climate areas. Elsewhere they are temporary inhabitants of our flower beds.

Kenwood is in London so Kentish Bell might possibly be growing there. There is a Poncirus trifoliata round the back of St Pauls (Paternoster Square) which shows how mild it is. Frost is rare in Central London. I had a look at the 'barren' bed and it looks to me as if it is awaiting planting of the Summer bedding.

Kenwood House is not situated on public roads so I can't use street view on it.

Anyway our OP seems to have disappeared so, yet gain, we are to talking to ourselves.

"Anyway our OP seems to have disappeared so, yet gain, we are to talking to ourselves."
Yes, something of an epidemic of that around here.

FWIW I would have expected Poncirus to be hardy almost anywhere in the UK (maybe not the top of Ben Nevis) as they are solidly zn 7 hardy in the US, and found in many, many 6b or even 6a locations. It's possible they don't harden as well with your mild summers, but I seem to recall stumbling upon a page of someone in the north of England who was growing (outside) several "hardy citrus" that are not as hardy as Poncirus.

Well - you live and learn. The Poncirus I saw at St Paul's is the only one I've ever seen. But having looked it up it does appear to be hardy. But clearly not popular. Maybe we have enough prickly things to choose from without adding another.

The tree turns out to be Crinodendron hookerianum, as originally thought.

Here is a link that might be useful: Other post on this tree.

Why couldn't she have posted the picture here!? Oh well, glad that's sorted.