Identification: Please help identify...is it dangerous?

Hello!
A friend of mine came across this plant in the Washington D.C. area. We were both amused by the strange "branches" and the lemon-like "fruit" that it produced. Upon mentioning that it would be fun to have around because of it's unique appearance, he mailed one of the "fruits" to me in the midwest.

First of all, I want to be sure that it's not dangerous, as I have pets in my home. And secondly I would love to identify what sort of plant it is. Lastly, if anyone has any advice on how to plant the fruit that would be helpful. I'm new to this.

Thank you for any insight you can provide!!!!

 

Looks like Poncirus trifoliata 'Flying Dragon', Trifoliate Orange. I don't think it's dangerous unless you run into its thorns. Plant the seed as you would with other types of citrus seed. You'll find the necessary information by searching the Citrus forum.

 

The fruit can be used to make marmalade. Very sour, so it needs lots of sugar adding.

 

This may help you .
http://www.homecitrusgrowers.co.uk/poncirustrifoliata/poncirus.html