Here in England there's an excellent nursery called Hilliers that produces a book listing all the trees and shrubs that are hardy in the British Isles.
Up until the 1970's they used this book as a catalogue and claimed they would propagate any plant listed. Included was the species 'XCitroncirus Webberi', better known to citrus growers as 'Citrange'.
I think it was in 1976 that I ordered a XCitroncirus Webberi from Hilliers. Back came the reply - very sorry, we are no longer stocking or propagating plants with little demand from customers.
So, I ordered and planted a couple of Poncirus trifoliata instead, both of which thrived and are now mature and fruiting.
But ever since then I have been keeping an eye open for a Citrange growing in England. Though over the past 30 years, I must have visited hundreds of gardens, I've never found one.
Last week, I received an e-mail, asking me to identify a citrus fruit growing outside somewhere in England. Bound to be a Poncirus, I replied.
But, a follow-up e-mail claimed the fruits were 2"-3" diameter, and much like the picture of a Willets Citrange shown on my website.


Two photos of the fruits were included with the e-mail:


It really didn't look like a Poncirus fruit. Much more defined segments, and a pithy central core.
Where is it?, I asked, starting to get interested. Well, it turned out to be in the garden of a closed-for-renovation museum in the city of Leicester, about two hours drive from me. So I phoned the museum, negotiated permission to look round the garden, and set off.
I found the 'citrus' in the museum garden.
It was a Poncirus trifoliata, no doubt about it.
Yes, the fruits were on the large side. And one or two had a kind of navel, which I haven't seen on Poncirus fruits before.


It was one of these slightly unusual fruits that had been photographed and had the pithy core. But otherwise, it was a standard Poncirus with deciduous leaves starting to drop.
A considerable disappointment, and a somewhat wasted 4 hour drive.
And the search for an English citrange goes on!
Mike

Very interesting Mike, thanks. Good luck in your quest for the Citrange!

Ned

Too bad citrange! If you are ever on this side of the pond, I can hook you up with the real deal in about 10 minutes or less. Do you have any idea why the trifoliate oranges from this particular tree are producing such unusual fruits?

Hi Mike,

even if you was disappointed about the final result, the shape of these fruits is very amazing. Something shoud have caused this and it would be nice to know, what was the reason for the navel.

Regarding Poncirus I visited in between a lot of different trees at different locationes from different origens. Finaly a came to the conlusion that variation of fruits is not caused by special clon. E.g., my Poncirus tree has 4 different shapes of fruit:









The one´s with the smooth peel are most seedy. However a navelfruit I never saw. If this is stabil each year, it would be very attractive to have. Concerning the Hardy citrus community at the UK I also wonder, why there is not a larger number of gardeners trying these citrus. Conditions are normaly much better than in our area. My be the only way to promote this is if you spend plants for neighbours or the related gardeners for public gardens.

BTW a couple of minutes ago we had a nice rainbow over my small citrus corner(happens not very often here)...



Best regards

Andy

I've no idea what could cause the navel in the Poncirus fruits - apart from 'it's in the genes'. There was certainly no special treatment given to that plant. There were only a few navel fruits among the fifty or so on the tree.
Although I agree with Andy that P.T. fruits do vary quite a lot on a single tree, there are certainly variations between plants. For instance, the surface of the fruits on my PT's are fairly smooth, but I recently came across one specimen (Cannizaro Park, south London), that had very pebbly fruits:



Mike
(Citrange)

May be the navelfruit was caused by a special kind of mite during or short after pollination. Once I had also an amazing affect at my Salustiana. It resulted in a fruit which was partly looking as buddhas hand ...see 2 fotos below:





Only an Idea...

Bye

Interesting different fruits :

http://www.citrusy.cz/forum/viewtopic.php?t=626

(Forum Czech Republic)

Perhaps this will help and may confuse the issue even
more but there is a trifoliate that can produce a navel,
as part of its genetic make up is from a Navel Orange
parent. Look at Carrizo and Troyer citrange as examples.

Much of the information near the bottom of the first link
page regarding X Citroncirus webberi were works of which
some of the resulting varieties were rather popular used for
rootstocks for Citrus a way back when. I believe some of
our dwarfing forms of rootstocks came from a few of them.

Sorting Citrus relatives

http://www.plantnames.unimelb.edu.au/Sorting/Citrus_relatives.html

This link below gives more insight into the names.

Sundry Hybrids and Rootstocks

http://www.hort.purdue.edu/newcrop/morton/sundry_hybrids.html

Jim