Washingtonia is a genus of two large, fan palms - one native to Southwest U.S. and the other to Northwest Mexico. Although neither are native to deep south Texas, both have naturalized here.
California or Desert Fan Palm, Washingtonia filifera is indigenous to California and western Arizona. It grows to 60 feet tall and has a stout trunk. Filifera's leaves have a white threads between the split segments.
Mexican Fan Palm, or Washingtonia robusta, is native in the Mexican state of Sonora and the southern Baja California. It is a taller, thinner palm, growing to 90 feet.
Washingtonias cross-pollinate easily so a "pure" species is hard to identify and possibley rare. Both are pretty cold-hardy, surviving temperatures in the 20s (or hardiness zone 8).
This is the most common palm in the Rio Grande Valley, lining roadways, both large and small. It's great in large commercial developments. The size of this palm makes it unsuitable for your average home or yard. But if you happen to have a 3 story home or large yard. it would be a great addition to your landscape.