Operating system: Ubuntu 18.04.3
Graphics card: AMD RX 580
Broken: 2.81 125257758007
Short description of error
This glitched viewport happens if you append the tree object in a new project in 2.81.
Exact steps for others to reproduce the error
The glitch happens only if you never go in material or rendered modes before appending the object.
So, open Blender 2.81, let everything as it is by default, click on File > Append and append the "American Beech" and "Leaves American Beech" objects.
Switch to material preview or rendered.... the tree is glitchy.
But, if before appending the object, you switch to material preview or rendered mode and then append the two objects then you will see it textured correctly.