Flowering plants are divided first into these two classes, the Dicotyledons and the Monocotyledons.
"Outlines of Lessons in Botany, Part I; From Seed to Leaf" by Jane H. Newell
CLASS I. DICOTYLEDONES ANGIOSPERMEAE, called for shortness in English, DICOTYLEDONS or DICOTYLS.
"The Elements of Botany" by Asa Gray
CLASS I. DICOTYLEDONOUS PLANTS.
"The Manual of the Botany of the Northern United States" by Asa Gray