need ID on multi-lobed spiny plant

Please help me id this plant. It is growing in 2 or 3 of my small garden areas. We have many birds and squirrels so may have been planted by one of them. I need to know if it is a plant to keep or if I need to pull them. Thanks, Starfish

 

Looks like Solanum rostratum Buffalobur. Try this link for comparison:
http://dallas.tamu.edu/weeds/desc/buffalobur.html

 

Thanks for your help identifying this plant. Doesn't sound like I want it to grow in my garden.