Light green leaves, bluish purple flowers, yellow berries or seeds and has stickers or small thorns on its stem. Very long tap root and will regrow if you don't pull it all up.
What Type of Weed Is This and How Do I Kill It ?
Certified GKH Gardening Expert
Sounds like it may be Devil's Apple (also known as Apple of Sodom), which is a common but hateful weed in TX.
Here is more information on it: