furcate
To fork or branch out.
These ridges are prominent, about the thickness of a coarse thread, very numerous, irregular, and run into one another, but towards the bottom, always furcate or divide.
Where it comes from
From Medieval Latin furcātus (“forked, branched”), from Latin furca (“fork”), see -ate (adjective-forming suffix). Compare French fourchu. The verb was formed by metanalysis or as if from Latin furcō (“to fork”), see -ate (verb-forming suffix).
Adapted from the Wiktionary entry furcate (CC BY-SA 4.0).