the main long, thin part of a plant above the ground from which the leaves or flowers grow; a smaller part that grows from this and supports flowers or leaves （花草的）茎；（花或叶的）梗，柄 
long, trailing stems of ivy 常春藤长长的蔓生茎 a tall plant with branching stems 有分枝茎的高大植物 There are several leaves on each stem. 每一根茎上都有几片叶子。 When the bush has finished flowering, cut back all the stems. 等这丛灌木开完花后，把所有的茎干都修剪一下。
Oxford Collocations Dictionaryadjective- long
- tall
- short
- …
- break
- cut
- cut back
- …
- break
- on a/the stem
- the base of the stem
the long, thin part of a wine glass between the bowl and the base （高脚酒杯的）脚 
the thin tube of a tobacco pipe 烟斗柄 - -stemmed
(in adjectives 构成形容词 having one or more stems of the type mentioned 有…茎（或梗）的 a long-stemmed rose 一枝长茎玫瑰 slender-stemmed wine glasses 细茎酒杯
- (
grammar 语法 the main part of a word that stays the same when endings are added to it 词干
Word Originnoun Old English stemn, stefn, of Germanic origin; related to Dutch stam and German Stamm. Sense (4) is related to Dutch steven, German Steven.
Idioms
from stem to stern
all the way from the front of a ship to the back 从船头到船尾