The shading of the Mangrove Roots' inner planes is inconsistent when multiple of them are placed together in the X axis. The block on the west end will always be darker, while the ones in between the two ends will always have their planes as bright as their outer cubes.

The darker shading only affects roots that have solid blocks underneath (see attached picture), and with smooth lighting turned on. The fully bright inner planes can be observed in any situation, although it's subtle.