běn
root
Addition of a horizontal line toward the bottom of 木 (tree) to represent the roots of the tree.
Bronze script
Seal script
Clerical script
Regular script
běn
root, origin, source; basis; root; stem; origin; source; this; the current; original; inherent; originally; classifier for books, periodicals, files etc
季旭昇《說文新證》p.484-485