What are the mushroom columns in the S.C. Johnson administration building?

In the administrative center for S.C. Johnson in Racine, Wisconsin, Frank Lloyd Wright utilized novel, tubular mushroom columns to support the structure.1

These columns are a defining feature of the building's interior, helping to create an airy, open-plan workspace that is widely considered one of the most humane workrooms in modern architecture. By combining these unique supports with a closed, top-lit design and recurving forms, Wright achieved a sense of spaciousness and innovation that demonstrated his mastery of expressive, functional design.1