The duration on this appears to be wrong. It is currently 36 seconds or 6 "ticks".
This thread is old as hell and says that Enstill lasts longer than "Root":
https://web.archive.org/web/20010306...enchanter.html
Root is currently 36 seconds, so it's the same duration as Enstill. (Perhaps another issue is that the wiki shows root as lasting "2 ticks @L4 to 8 ticks @L14", when in fact Root only lasts 6 ticks...)