He studied law in Montpellier, during which time, he developed a passion for botany.
He was a friend and collaborator to Scipio Maffei, with whom he took an extended scientific tour throughout Europe (1732–36).
[1] In 1755 he became a member of the Académie de Nîmes, serving as its secrétaire perpétuel from 1765 to 1784.
[5][6][7] His written works include a detailed description of the flora in the vicinity of Verona, titled Plantae Veronenses, seu Stirpium quae in agro Veronensi repriuntur (3 volumes 1745–54).
[8] Other noted works associated with Séguier are: The standard author abbreviation Ség.