It's probably poncirus trifoliata if it's like the ones I saw in East Tennessee in the 70's. Mostly thorns, relatively few leaves that come in threes, perfumed sort of fuzzy fruit. Lovely thing. Will grow as far north as Philly or even further if sheltered. Here's a link: http://www.eattheweeds.com/hardy-orange/

Thanks for the comments everyone - I just had a chance to review them. I must say, overall, I am just amazed at how well most citrus do so close to the ocean(less than 1 mile). Of course they do show signs of some stress - lots of bronzing of the leaves from the salt air. I also have a mango tree that is doing great. Maybe this is an idea to help solve world hunger! All we need to do is replace the ocean front condos with citrus tree groves! My trees are all in-ground and average 6 ft - they are all doing their fall growth spurt right now. I found that the trees will only survive the hurricanes if they are somewhat protected, kept short and compact, and staked for support. My neighbours lost their large grapefruit trees recently from hurricanes, so I plan on really keeping it short (10 ft). The meyer's lemon always gives a nice little crop (10), as does the grapefruit (100). The limes give a small crop so far (3 or less). I agree with the root stock idea. Some just seem to love the soil/ocean mist. I have two citrus rootstocks that came up "wild" for free about a foot from the respective mother trees. The first is from a meiwa Kumquat, the second is from a sunburst tangerine. The kumquat, incidently is quite healthy and productive, however the tangerine never flowers. The Kumquat rootsock may have been from seed, I can't be sure. Anyway, both stock look exactly the same -big simple dark green leaves no tri-folate shape, growing straight up, and giant 1" -2" long thorns. One I planted in the same hole where the dead Temple Orange was (about a year ago), and the other is in a pot. They are both about two years old. They both grow very fast and vigorous (faster than any of my other trees). The one in the ground is already about 24"" high. Does anyone know what rootstock this is?? So anyway, I agree it might be a great idea to graft on to them - I just need to learn how to do that.

Alan,could you tell me the reason for wanting a Satsuma on a trifoliate rootstock? Also who and where are the "just Fruits folks". I also want to plant a Satsuma. Felix My reason for wanting the Satsuma on Trifoliate is that my dad lives in southern central Georgia which is pushing the envelope for edible citrus. Satsuma is pretty cold hardy, but as it's eventually going to be an outside tree it's going to need the additional cold resistance the trifoliate can give it. There is one variety of trifoliate known as Flying Dragon that can serve to dwarf a tree for a time so it popular for that reason. Trifoliate orange is different from sour orange which at one time was very widely used in Florida, but has declined due to its susceptibility to the tristeza virus. For you folks down to the central part of Florida there are other rootstocks available that you might want to consider such as Swingle or Cleopatra tangerine. Swingle is the most common rootstock in Florida now due to its vigor, degree of cold hardiness and resistance to the tristeza virus. Chances are pretty good though that most nurseries won't have any idea what the trees they are selling are grafted onto though once in a while you'll come across one that does. The breeder nursery tag should be on the tree so if you really want to know you can call them. I did this a few years ago with some citrus I bought from my local Lowes. It turns out that Record Buck Farms propagated the trees I bought so I called them to ask questions. I got their phone number by Googling their nursery registration number on their tag. .....Alan.

'Edible'? Maybe. Most I've encountered have this really nasty oil in the rind that pretty well precludes their use as an edible fruit - but I had a friend send some he'd found at an old homestead in MS that had thinner rind - and less oil - than those I've encountered growing up here in KY - and while it still had minimal pulp and LOTS of seeds, I guess I could call it edible - but it's still something of a stretch. Most P.trifoliata comes 'true' from seed - so, for instance, if you get fruits from the contorted 'Flying Dragon' selection, its seedlings will display the same contorted growth habit and curved thorns.