a pic of inside. Most are yellow but some are orange and I think those are more ripe.?

Sour Orange or Bitter Orange or Seville Orange is Citrus x aurantium (subsp. amara according to some, amara meaning bitter). They are the same citrus and the extent to which the different varieties may differ is similar to the difference between Washington and Valencia sweet oranges for example. Different cultivars of course exist but they are the same citrus tree. All of them produce bitter-sour round fruit, with more or less coarse rind which becomes deep orange in maturity (at least when grown in a med type climate). and pale yellow--greenish pulp. The leaves have a pronounced elongated petiole and the tree usually carries some long thorns on the more vigorous shoots. Bitterness is extremely pronounced so the name 'sour orange' is kind of a misnomer. Yes they are sour but most of all they are bitter. The fruit is inedible when raw regardless of the level of maturity. They have a distinctive perfume both in the rind and in the leaves which cannot be confused for other citrus. This is what has been used for rootstock for centuries and for English 'Orange' Marmalade. I don't know what might be called sour orange in the Americas but if it is not what I have described it is not Sour Orange. Not every sour tasting 'orange' is a Sour Orange. The name 'Seville Orange' is of course an old name the English importers gave it a long time ago and may now be a legally protected name. But this is just a commercial issue. In Greek the name for the tree 'nerantzia' has the same roots as naranja and aurantium. The trees were introduced in the Med region before sweet orange was. Bergamot is really a different citrus, most probably a cross between SO and a limetta (which gave it its distinctive flavour). In the East Med we grow sour limettas which carry the same perfume as Bergamot orange but look like lemons or citron.

This is the same tree on US897 rootstock from seeds you sent me. In a 10 gallon pot Closer look. Pip You don't have to stay in Arizona. If you come to Cincinnati. you can have most of my remaining rootstock (US897 and C35). My wife and I are not in a financial position to be shipping trees. If any one else passes through Cincinnati and wishes to get my extra root stocks let me know and I' make arrangements to meet. Steve PS Citrus trees grow better in Cincinnati than Arizona.

Bob I think that most people get to many varieties and burn out on the associate problems and end up quitting. I know of several past people who lost power to their green house and lost 30 to 40 trees. They looked for more trees with advice from us and then left. These trees are expensive. If I decide to quit citrus I will let you all know and why. When I first started I posted a lot with picture and a lot of other people got mad and they let me know in very rude ways. I am still here and Better than 15 of them are gone. It is too bad because they were a real asset to the group Jay We eat them like an orange or mandarin. Gave away 1 each to 4 closest friends. It is well worth growing. I have eaten 45 fruits total from 3 different trees. Steve