Archtree

Archtrees are a kind of lifeform native to planet Koehler in the Orion's Arm universe.

Biology
An archtree blurs the boundary between plant and animal life. Externally, each specimen looks like a leafless purple trunk with branches at both ends. The trunk may either be straight or bent, with both ends of branches touching the ground in the last case.

However, they are distinct from plant life because they move very slowly, by bending over and digging their branches into the soil temporarily, in a process that can take up to months or years.