A descendant of Sugane, his son, Motokata, who climbed from monjosho to Dainagon (chief councilor of state) and others did not follow (his great grandson and the grandson of Motokata or FUJIWARA no Yasusuke was famous bandit) but Monjo hakase (professor of literature) was picked from the Southern House of the Fujiwara clan with him as the forerunner.
菅根の子孫は息子・元方が文章生から大納言に昇って以後は振るわなかった（菅根の曾孫・元方の孫の藤原保輔は盗賊として著名）が、彼を先駆者として藤原南家から文章博士が輩出されるようになった。