Planted this from a nursery labeled "mandarin orange". I'm guessing that the orange branch had been grafted onto something else and died. Maybe ornamental fruit? Definitely not edible... Has been giving fruit for a few years now. Smells a little like a lemon only EXTREMELY bitter -- so bitter you can't even taste a little without brushing teeth.

Original thought it was some exotic disease, but the tree/leaves don't show any of the symptoms for those diseases.

Any ideas what it could be?

Fruit on tree
http://imageshack.us/a/img545/7436/gwaq.jpg

Fruit on tree 2
http://imageshack.us/a/img853/2371/7bgs.jpg

Inside fruit
http://imageshack.us/a/img196/2043/d2qa.jpg

Leaves
http://imageshack.us/a/img202/6913/h3tg.jpg

Leaves #2
http://imageshack.us/a/img202/7117/2psb.jpg

Limbs
http://imageshack.us/a/img440/1470/wszj.jpg

Trunk
http://imageshack.us/a/img855/5581/xonb.jpg

"Guv Bob" wrote in message m...
Planted this from a nursery labeled "mandarin orange". I'm guessing that the orange branch had been grafted onto something else and died. Maybe ornamental fruit? Definitely not edible... Has been giving fruit for a few years now. Smells a little like a lemon only EXTREMELY bitter -- so bitter you can't even taste a little without brushing teeth.

Original thought it was some exotic disease, but the tree/leaves don't show any of the symptoms for those diseases.

Any ideas what it could be?

Fruit on tree
http://imageshack.us/a/img545/7436/gwaq.jpg

Fruit on tree 2
http://imageshack.us/a/img853/2371/7bgs.jpg

Inside fruit
http://imageshack.us/a/img196/2043/d2qa.jpg

Leaves
http://imageshack.us/a/img202/6913/h3tg.jpg

Leaves #2
http://imageshack.us/a/img202/7117/2psb.jpg

Limbs
http://imageshack.us/a/img440/1470/wszj.jpg

Trunk
http://imageshack.us/a/img855/5581/xonb.jpg

===

This is the best match I could find.....

Leaves: Alternate, Compound, Trifoliate

===

http://idtools.org/id/citrus/citrusi...foliate+Orange

Citrus L. (sec. Mabberley 2004, Bayer et al. 2009); Poncirus Raf. (sec. Swingle and Reece 1967; Cottin 2002)

Pseudaegle Miq. (sec. Swingle and Reece 1967)

Poncirus stands alone in [the true Citrus fruit trees] in having » Trifoliolate: A compound leaf consisting of three leaflets. "trifoliolate, » Deciduous: Falling off. "deciduous leaves and winter buds well protected by bud scales. It has pleiomerous ovaries with six to eight locules, with many ovules in each locule. In these ovarial characters it agrees with Microcitrus and Citrus."

===

http://homeguides.sfgate.com/mean-gr...-it-60692.html

Trifoliate Orange

Trifoliate orange (Poncirus trifoliata) is a member of the citrus family Rutaceae. Trifoliate refers to its leaflets of three leaves. This tree has such formidable thorns that Dr. Hugh Conlon, retired extension horticulturist, calls it "the barbed wire of the plant world." Also called hardy or bitter orange, trifoliate is often planted as an impenetrable hedge. Although it also bears fruit, they are seedy and sour tasting. Its greatest commercial value lies in the hardiness of its roots, which make it a preferred rootstock for grafting sweet orange trees. Its thorns, however, will continue to grow below a graft union or bud, even on citrus trees that do not typically bear thorns.

===

http://en.wikipedia.org/wiki/Citrus

Trifoliate Orange, Poncirus trifoliata (syn. Citrus trifoliata), is a member of the family Rutaceae, closely related to Citrus, and sometimes included in that genus, being sufficiently closely related to allow it to be used as a rootstock for Citrus. It differs from Citrus in having deciduous, compound leaves, and pubescent (downy) fruit.

It is native to northern China and Korea, and is also known as the Chinese Bitter Orange.[1]

They are very bitter, are not edible fresh, but can be made into marmalade, and when dried and powdered, they can be used as a condiment.

The fruits of Poncirus trifoliata are widely used in Oriental medicine as a remedy for allergic inflammation

Poncirus trifoliata extract could possess a wide range of beneficial activities for neurodegenerative disorders.[

Neurodegeneration is the umbrella term for the progressive loss of structure or function of neurons, including death of neurons. Many neurodegenerative diseases including Parkinson's, Alzheimer's, and Huntington's occur as a result of neurodegenerative processes.