Rochester (or American) Code 1890-1930
Concept of types to determine the precise application of names.--Name always goes with the type specimen.
- holotype--specimen designated as the type by the author at the time a new species is described
- isotypes--duplicate specimens of the holotype (collected at the same time and in the same place).
- syntypes--some old-time botanists would designate several specimens to represent what their name referred to. Botanists today have to choose among them and designate a lectotype (holo- and iso-)
- If no type specimens are extant then botanists must choose a neotype.