Here are a couple of pics of an unknown citrus my sister sent me from northern California. The original calamondin died back to the rootstock and this grew up. She says they are really sour. Any ideas on the identity?

http://img44.imageshack.us/img44/3024/unknowncitrus3jpg.jpg

http://img178.imageshack.us/img178/2434/unknowncitrus2jpg.jpg

Could be a Citrumelo, but really you need photo of leaves - and also the fruit clearly isn't ripe.

Its a pretty shade of green though.

Yes, I know it isn't ripe. She said the wind knocked it off the plant.

Here are some pics of the leaves from some time ago.

http://img151.imageshack.us/img151/8774/photo4th.jpg

http://img249.imageshack.us/img249/9449/photo1bs.jpg

I'm no expert but the best guess I have is Cuban Shaddock based on the large number of segments with curved edges, thick peel, number of seeds, fruit shape, size, and surface texture, short petioles, long curving single leaves, its use as a rootstock, and coming from northern California. However, the fruit is not flattened on the end and the core is not open so I am really not sure.

Looking at leaves, it can't be any of the citrumelos, citranges, shaddock/pummelo, sour orange, or sweet orange. It also is not a true lemon, rough lemon, alemow (C. macrophylla), nor rangpur lime. So at least we know some things it is NOT! But as to what it IS, I don't know.
Malcolm

Cuban Shaddock???, it looks pretty close, and it began as a rootstock. The seeds look fairly small for a big fruit. the flower structures are large and also in clusters. The leaves look about right, still might be an off type seedling of Cuban ?