An article published in the International Journal of Plant Sciences was brought to my attention by Bob Polomski, Ph.D., Extension Associate, Clemson University, indicating that Baldcypress knees do indeed function as pneumatophores.
See citation below for article text:
Martin, C. E., & Francke, S. K. (n.d.). Root aeration function of baldcypress knees (Taxodium distichum). International Journal of Plant Sciences, 176(2), 170–173...