It could also be a Viburnum dentatum cultivar. My 'Chicago Luster' is starting to leaf out and it looks like your photo. One yours gets totally leafed out and blooms, an exact id can be made. Whatever cultivar it turns out to be it will be good. I've never met a viburnum I didn't like : ) Remy Here is a link that might be useful: Viburnum dentatum

The tree looks similar to the invasive Chinese Tallow Tree (Triadica sebifera). Take a look at this link for further identification. If it is a tallow, you might want to consider getting rid of it before you and your neighbors develop a Tallow-tree jungle! Here is a link that might be useful: Invasive Species Tallow-tree

Looks like Frostweed. It's a very prolific self seeder in my garden. I'm out of room for anymore. They grow fast and bloom the first year. Great for pollinators. Verbesina virginica most likely. You have more Verbesina species down there that I'm not familiar with. There are 2 other white flowered Verbesina in Texas, V. microptera and V. walteri. All 3 white flowered species have very different flowers.

Are the leaf edges completely smooth, or are there serrations? Possibly Ilex decidua? EDIT: Embo beat me by a couple of minutes. I was trying to enlarge the pic to see the leaf edges. I'm *fairly* certain it's I. decidua.