I've gotten Whipper Root Tubers in 3s, 5s, 6s and 7s.



I found Whipper root in the location marked in red.

For Rogues, Warriors & other classes with no inherent healing, Whipper Root Tubers are great for extra consumable-source healing besides Potions.  Healthstones disappear after log off and time, but you can gather lots of extra Whipper Root Tubers and keep them for your adventuring, whether solo or group.