Maybe the thick rinded kind is being used for rootstock by grower(s), with the previous example being left from when a desired citrus was grafted onto this kind. And planted there. With your replacement grafted combination also having the same big yellow kind being used for the rootstock. Or you didn't get all of the thick rind kind dug out, and it sprouted and grew up through the new planting.

Cuban shaddock rootstock is the lemon like fruit. I found the fruit to be better tasting than the Meyer lemon if you could penetrate the peal and pith.

Steve, is the inside of the fruit juicy or dry?

Sunshine: The oranges are juicy and sweet and the lemon is on the drier side but I was able to get some juice out of it.

It is possible this is Cuban shaddock rootstock that sprouted from beneath the graft. Check carefully and cut if you want oranges. What is the rootstock of the replacement orange?

Embothrium: I just asked my husband and he did not get all of the roots of the lemon tree out when he planted the orange tree. I looked and it’s all one tree. All the branches are coming from the same trunk. This makes me think the roots somehow merged together?

It was a good balance of flesh and juice. The peal was very hard to remove but at 7 inches I had a 5 inch ball of seedy flesh. All the seeds were in the sections center crease. I ate mine out of hand. I considered the tree not worth growing and I let both of them die over the winter, They were very aggressive growers and put out 8 -10 foot shoots that I could not protect.

30 gallon transplant into ground

12 foot tree freezing to death

8 foot diameter at 6 feet tall

It is big

Steve

Deanna, roots do not merge to make a dual fruit tree. Check your graft ... and which branches may be growing above or below.

What did the tag say as to rootstock ID?

Thanks molewacker. I’m not sure what the rootstock ID was as the tree is several years old. There are no longer any tags. Just trying to figure out why we have large lemons and oranges on the same tree? I just re-read your earlier post, just to clarify we can cut the branches that grew the lemons and we should just get oranges next year?

Citrus maxima 'Cuban Shaddock'

http://citruspages.free.fr/pomelos.html#cuban

Dave- Thank you. It is raining here so will get some pics as soon as I can.