Within the limits set by that code there is another set of rules, the International Code of Nomenclature for Cultivated Plants (ICNCP) which applies to plant cultivars that have been deliberately altered or selected by humans (see cultigen).
Botanical nomenclature has a long history, going back beyond the period when Latin was the scientific language throughout Europe, to Theophrastus (c. 370–287 BC), Dioscorides (c. 40 – 90 AD) and other Greek writers.
From Mediaeval times, Latin became the universal scientific language (lingua franca) in Europe.
[1][2][3] Leonhart Fuchs, a German physician and botanist, is often considered the originator of Latin names for the rapidly increasing number of plants known to science.
For instance he coined the name Digitalis in his De Historia Stirpium Commentarii Insignes (1542).
Some protists that do not fit easily into either plant or animal categories are treated under either or both of the ICN and the ICZN.
Another term is ambiguous to denote a name that is not accepted because its separate existence cannot be reliably determined.