The core idea of this root was:
stemming, putting down firmly, a solid stem
The theme is definitely a bit vague, but we can see aspects of it in the English offspring
- step (putting down the foot)
- staff (putting down a walking aid)
- staple (originally, this could be a pillar or tree trunk and even a stairstep – basically something you can rest on.)
- stamp (“put down firmly”)
The word stem, even though it would fit right in here, does not belong to this family and instead comes from a different root.