Yaupon Holly is a unique and well known plant in central Texas. It is a shrub that grows about 12-45ft tall. The female plant is easily identifiable with bright red berries. It is a unique plant because the leaves contain caffeine. Yaupon Holly is the only native plant in Texas that contains caffeine. Native Americans would dry and crush the leaves to make a tea to drink. They used the tea as part of rituals and would drink a lot of it and throw it up. However, the leaves do not cause vomiting. It was also commonly given to guests but not in large quantities. You might even see Yaupon Holly leaves sold in stores as a tea!
Yaupon Holly is an evergreen shrub so it is used in many landscapes as well as in restoration plots. It is very popular in the winter because of the dark green leaves and bright red berries. In order to have the red berries you need both male and female plants.
My iNaturalist post can be found here.
references:
http://www.wildflower.org/plants/result.php?id_plant=ILVO