non-woody       
adjective (also nonwoody) uk/ˌnɒnˈwʊd.i/ us/ˌnɑːnˈwʊd.i/
 非木本植物的
Non-woody plants do not have hard stems.
  The potato is the tuber of a non-woody plant native to South America. 马铃薯是一种原产于南美洲的非木本植物的块茎。 
 Herbaceous plants are always non-woody and die at the end of a growing season. 草本植物绝非非木本植物,会在生长季节结束时死亡。 
 - More examples
 - The flowerbeds were full of non-woody plants such as asters, peonies, hostas, and several different varieties of grass.
 - Remove the woody part of the stem and finely cut the non-woody part.
 - Although it has a low energy content, nonwoody biomass made from agricultural waste can be used as a substitute for fossil fuels.