Despite being known for it's chivalry and southern hospitality, Texas can be Very Shady. My particular favorite is the Southern Red Oak (Q. falcate)

Printed on a soft Cotton/poly Next Level brand men's tee. 

These shirts run pretty true to size and I would just order whatever size your normally wear in a men's shirt. They are 60% cotton however, so after the first wash, it is natural for them to draw up just a tad in the body length and sleeves.