Ostrya chisosensis

About

Ostrya chisosensis, common name Big Bend hop-hornbeam or Chisos hop-hornbeam, is a plant species endemic to Texas. It is known only from the Chisos Mountains inside Big Bend National Park, in Brewster County, although related populations in northern Chihuahua have not been studied in detail and may be the same species. It grows along streambanks and on the walls of canyons.

Summary from Wikipedia