Lemuel is a Biblical name (Pr.31:1, 4) but is was also the name of a neighbor of Joseph Smith, Lemuel Durfee, who signed an affidavit in 1833 that denounced Smith's supposed revelations and accused him of immoral character and vicious habits. (See Howe's Mormonism Unvailed, p. 261-2)
Lemuel was one of the bad guys that God cursed, causing him and all his descendants to have dark skin.