[buht-er-bur] 
| any of several composite plants of the genus Petasites, having large, woolly leaves said to have been used to wrap butter. |
| but·ter·bur (bŭt'ər-bûr') n. Any of several perennial herbs of the genus Petasites in the composite family, native to northern temperate regions and having large basal leaves and dense clusters of usually whitish or purplish flower heads. |
ərˌbɜr