From the Super Mario Wiki
Mario inside a trees Sap attached to the ceiling

Sap[1] is a gelatinous substance found in the Tree Zone in Super Mario Land 2: 6 Golden Coins. Mario can use it to get across spikes by jumping inside and "swimming" through it to a safe area. It only appears in Tree Zone Area 2 where it is on almost every wall and fills the small gaps between floors. Mōgyo swim inside it, adding to the difficulty of traversing it.


  1. Nintendo Power Volume 43, page 41.