Hello. My wife and I recently moved into a new home and we are having difficulty identifying our backyard tree. There is a gardening tag at the bottom that states 'Eureka Lemon' but this tree has large thorns which is not a characteristic. The fruit is larger than any lemon I've seen and looks more like a grapefruit. The previous tenant said it was a lemon tree?
Also, the tree seems to have some problems, possibly disease: Sap oozing from the bottom of fruit, small brown bumps all over the trunk and branches and finally ants crawling limb to limb.
I would really appreciate any help we would like to save this tree if possible. Thanx in advance!!
Example of fruit (Ignore the toy):
Are these brown bumps a sign of disease?:
Oozing lemon another sign of disease?:
Finally, a shot of the fruit cut in half: