Longest and shortest names

General remarks

Recommendation 6 (1) of the ICNP (2008 Revision) states the following: "Avoid names or epithets that are very long or difficult to pronounce". In spite of Recommendation 6 there are some long monomials and epithets. The longest and shortest names validly published under the ICNP are listed below, assorted by their taxonomic category. Epithets of species and subspecies are treated separately. In the case of species names the count of characters includes the space; in the case of subspecies names the count of characters includes the spaces and the subspecies indication. Other things being equal, taxonomists are advised to propose names and epithets whose length is as close as possible to the modes (the most frequent values) of the lengths listed below for each category.
See also the LPSN introductory page on forming names.


Longest: EpsilonproteobacteriaMethanonatronarchaeiaThermodesulfobacteria (21 characters)
Shortest: Bacilli (7 characters)
Average: 13.57 characters
Median: 13.00 characters
Mode: 13 characters (lower), 13 characters (upper)


Longest: Desulfonatronovibrionaceae (26 characters)
Shortest: Orbaceae (8 characters)
Average: 16.16 characters
Median: 16.00 characters
Mode: 16 characters (lower), 16 characters (upper)


Longest: ParatractidigestivibacterSphingosinithalassobacter (25 characters)
Shortest: BaiaPuia (4 characters)
Average: 12.58 characters
Median: 12.00 characters
Mode: 13 characters (lower), 13 characters (upper)


Longest: ThermodesulfobacterialesThermosediminibacterales (24 characters)
Shortest: Orbales (7 characters)
Average: 15.03 characters
Median: 15.00 characters
Mode: 15 characters (lower), 15 characters (upper)


Longest: Thermoanaerobacterium thermosaccharolyticum (43 characters)
Shortest: Baia soyae (10 characters)
Average: 22.88 characters
Median: 23.00 characters
Mode: 23 characters (lower), 23 characters (upper)

Species epithet

Longest: Clostridium saccharoperbutylacetonicum (26 characters)
Shortest: Cellulomonas udaLactobacillus uliOlsenella uliPseudoxanthomonas geiRhizobium geiSphingomonas gei (3 characters)
Average: 9.71 characters
Median: 10.00 characters
Mode: 9 characters (lower), 9 characters (upper)


Longest: Anoxyphotobacteriae (19 characters)
Shortest: AcidimicrobidaeCoriobacteridaeRubrobacteridae (15 characters)
Average: 16.29 characters
Median: 16.00 characters
Mode: 15 characters (lower), 15 characters (upper)


Longest: Gluconoacetobacter (18 characters)
Shortest: Acetobacter (11 characters)
Average: 14.50 characters
Median: 14.50 characters
Mode: 11 characters (lower), 18 characters (upper)


Longest: ActinopolysporineaePropionibacterineaeStreptosporangineae (19 characters)
Shortest: Frankineae (10 characters)
Average: 15.59 characters
Median: 16.00 characters
Mode: 14 characters (lower), 17 characters (upper)


Longest: Methylobacterium dichloromethanicum subsp. dichloromethanicum (61 characters)
Shortest: Winkia neuii subsp. neuii (25 characters)
Average: 40.46 characters
Median: 40.00 characters
Mode: 40 characters (lower), 40 characters (upper)

Subspecies epithet

Longest: Geobacillus thermodenitrificans subsp. thermodenitrificans (19 characters)
Shortest: Bifidobacterium longum subsp. suisCampylobacter lari subsp. lariClavibacter xyli subsp. xyliLactobacillus yamanashiensis subsp. maliLeifsonia xyli subsp. xyliLimosilactobacillus reuteri subsp. suisNocardiopsis alba subsp. alba corrig.Streptococcus equi subsp. equiStreptococcus infantarius subsp. coli (4 characters)
Average: 9.67 characters
Median: 9.00 characters
Mode: 8 characters (lower), 8 characters (upper)


Longest: Chromobacterieae (16 characters)
Shortest: Proteeae (8 characters)
Average: 12.17 characters
Median: 12.00 characters
Mode: 12 characters (lower), 12 characters (upper)