"stem of a plant," early 14c., probably a diminutive (with -k suffix) of stale "one of the uprights of a ladder, handle, stalk," from Old English stalu "wooden part" (of a tool or instrument), from Proto-Germanic *stalla- (source also of Old English steala "stalk, support," steall "place"), from PIE *stol-no-, suffixed form of *stol-, variant of root *stel- "to put, stand, put in order," with derivatives referring to a standing object or place. Of similar structures in animals from 1826.