What are the shortest and longest binomial names?
First, a quick refresher on binomial names. All organisms, living or extinct, are given a name by biologists to make identification easier across different languages and regions. These are called scientific, or binomial, names. A binomial name has two parts. The first part is the name of the genus, shared by closely related organisms. The second part is the name of the species, which identifies the exact organism. For example, humans are called Homo sapiens. We share the genus Homo with other, extinct human species, and sapiens (meaning “wise” in Latin) refers only to modern humans.
At just 11 letters, our binomial name is simple and easy to pronounce. Yet it is not the shortest assigned to an organism. That distinction belongs to the great evening bat of eastern and southeastern Asia. This member of the family Vespertilionidae weighing about 58 grams (2.05 ounces) with a wingspan of 0.51 meter (1.67 feet) bears the short name Ia io.
A popular but unsubstantiated story claims that its proposer, British zoologist Michael Rogers Oldfield Thomas, coined the name in 1902 in response to a challenge from American zoologist and botanist Gerrit Smith Miller to create the shortest possible binomial under the International Code of Zoological Nomenclature. The code requires at least two letters for both genus and species names, a condition Ia io meets.
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Unlike most binomials, which convey some information about the species, this name appears not to. However, a 2022 Royal Society article (“ ‘Shout hurrah!’ New thoughts on the origin and meaning of the bat species name Ia io, created in 1902 by Oldfield Thomas FRS”) suggested it may derive from ancient Greek and Latin, roughly translating to “shout hurrah”—perhaps a quiet celebration of Oldfield Thomas’s election as a Fellow of the Royal Society despite lacking formal education. As he left no explanation, this remains speculative. Whatever its origin story, it might be argued that as the shortest binomial composed entirely of vowels, Ia io gives scientists reason enough to shout hurrah.
Only one other binomial name has just four letters in it. Yi qi is the name given to an extinct dinosaur from the family Scansoriopterygidae. This dinosaur is thought to have had batlike membranous wings with a feathered edge. Its name translates from Mandarin as “strange wing,” a reference to its unusual flying appendage.
Among plants and microorganisms, the two other major life forms on Earth, the shortest names are longer than four letters. The Australian annual grass Poa fax has the shortest binomial name among plants. It is so named for its flame-shaped inflorescence, given that poa is Greek for “grass” and fax is Latin for “torch.” Although there is no clear consensus on which microorganism has the shortest binomial name, the funguslike oomycete Bremia o described in December 2025 appears to be a likely candidate. The specific name “o” is an exclamation in Latin, indicating the scientists’ surprise at the diversity of the genus and their discovery that Bremia o produces oblong to ovoid spores, which is rare in the genus Bremia.
The official name of Bangkok is Krung Thep Mahanakhon Amon Rattanakosin Mahinthara Ayuthaya Mahadilok Phop Noppharat Ratchathani Burirom Udomratchaniwet Mahasathan Amon Piman Awatan Sathit Sakkathattiya Witsanukam Prasit, which translates to “the city of angels, the great city, the residence of the Emerald Buddha, the impregnable city (of Ayutthaya) of lord Indra, the grand capital of the world endowed with nine precious gems, the happy city, abounding in an enormous royal palace that resembles the heavenly abode where reigns the reincarnated gods, a city given by Indra and built by Vishvakarma.”
The scientists who described Bremia o also described in the same research Bremia krungthepmahanakhonamonrattanakosinmahintharayuthayamahadilokphopnoppharatratchathaniburiromudomratchaniwetmahasathanamonpimanawatansathitsakkathattiyawitsanukamprasitnonopsis—an oomycete parasitizing the flowering weed hawksbeard (Crepis species). As of 2026 this is the longest species name in existence, bearing a total of 181 letters. The species name derives from the full official name of Bangkok—which has 168 letters in it—with a disclaimer included as part of the name that the species bears no resemblance to the city (nonopsis is New Latin for “not alike”). Why scientists felt the need to name the species after that city is unknown—it was collected in Germany.
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The International Code of Nomenclature for algae, fungi, and plants (Madrid Code, 2025) stipulates that species names published on or after the January 1, 2026, can be no longer than 30 characters.
Naming species based on where they are first sampled is not unusual. The record holder for the longest binomial name before it was displaced by the parasitic oomycete of the genus Bremia was the bacterium Myxococcus llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogochensis (73 letters) isolated from and named for the Welsh village of Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch.
The longest plant and animal binomial names pale in comparison. Ornithogalum adseptentrionesvergentulum (38 letters), a small flowering species from South Africa belonging to the family Asparagaceae, has the longest binomial name in the plant world. Among animals, the Southeast Asian soldier fly Parastratiosphecomyia stratiosphecomyioides (order Diptera, family Stratiomyidae) holds that honor with 42 letters in its name.
