Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
stem [stɛm] n (of plant) ствол* сте́бель*m (of leaf, fruit) черешо́к#; (of glass) но́жка#; (of pipe) черено́к#
vt (stop) остана́вливать (останови́ть*perf)
stem from vt fus (subj, condition, problem) происходи́ть*(произойти́*perf) от +gen
their aggressiveness stemmed from fear их агресси́вность порождена́ стра́хом
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.