Fig. S1: Deviation from the average for number of generic names, proportion of accepted names, average number of letters in generic names, and deviation from the average for generic name length per decade and century.

Rubiaceae is one of the most diverse angiosperm families and consequently is the topic of much systematic research. Plenty of literature exists on the familial, tribal, and species level; however, a comprehensive overview of the names at the generic level is lacking. The aim of this study is to present a survey of all names and designations at the generic rank in Rubiaceae and to uncover the context surrounding their establishment. Information about classification, authorship, publication date, type species, status (accepted or synonym), number of species, name length and initial letter, etymology, and stable identifiers is collected from literature and online databases. In addition, four aspects of naming (i.e., letters, authorship, date, etymology) are investigated in detail to look for patterns. Rubiaceae has 1386 generic names, of which 615 are accepted and contain 14,266 species. This makes it the fifth-largest angiosperm family based on the number of genera. The median number of species per genus is 4, but there are 191 monospecific genera. Of the 72 tribes, Spermacoceae has the largest number of generic names but 27 tribes are monogeneric, of which 12 are monospecific. Generic names are between 3 and 20 letters long and the distribution of the number of letters is a displaced Poisson distribution. Names beginning with P are the most frequent. Only 30 women were involved in the construction of 59 generic names, with a median publication year of 2010; for 98.2% of the names, men were involved. Europeans were and still are involved in the publication of the large majority of names. Almost half of the names appeared in the 19th century, but the proportion of accepted names increased over time. The average number of new generic names is 5.05 per year. Generic names more often have their origin in Greek than in Latin. The most common way of naming is referring to a plant feature, often reproductive characters. Eponyms, chiefly commemorating men, have always been common and even became dominant in the last two decades.