Complex sentence: He described a variety "sericea" from the Shoalhaven River region and also noted the discrepancy in a description of the species by Robert Brown, who noted the bark to be smooth, in contrast to Ferdinand von Mueller and others who recorded the bark as layered.
Split into simpler sentences: He described a variety "sericea" from the Shoalhaven River region and also noted the discrepancy in Robert Brown's description of the species. Brown had noted the bark to be smooth, in contrast to Ferdinand von Mueller and others who recorded the bark as layered.