Allium cepa
speciesAt a glance
Sources18 archives
Databases and archives Allium cepa's data was compiled from.
WikipediaWikimedia Foundation22 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility6 190 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI38 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics40 specimens↗
NCBIUS National Library of Medicinesequences↗
dukesphytochemcompounds
FooDBThe Metabolomics Innovation Centrecompounds↗
foodatlascompounds
LOTUSNatural Products (Wikidata)compounds↗
NPASSNat. Product Activity & Species Sourcecompounds↗
GRIN TaxonomyUSDA-ARSdistribution & uses↗
Open Tree of LifeOpenTreephylogeny backbone↗
CCDBChromosome Counts DB · Tel Aviv U.genome & karyotype↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
PloiDBPloidy Databasegenome & karyotype
Paleobiology DatabasePBDB consortiumfossil record↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
The onion (Allium cepa L., from Latin cepa meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus Allium. The shallot is a botanical variety of the onion which was classified as a separate species until 2010. Its close relatives include garlic, scallion, leek, and chive. This genus also contains several other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion (Allium fistulosum), the tree onion (A. × proliferum), and the Canada onion (Allium canadense). The name wild onion is applied to a number of Allium species, but A. cepa is exclusively known from cultivation. Its ancestral wild original form is not known, although escapes from cultivation have become established in some regions. The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season. The onion plant has a fan of hollow, bluish-green leaves and its bulb at the base of the plant begins to swell when a certain day-length is reached. The bulbs are composed of shortened, compressed, underground stems surrounded by fleshy modified scale (leaves) that envelop a central bud at the tip of the stem. In the autumn (or in spring, in the case of overwintering onions), the foliage dies down and the outer layers of the bulb become more dry and brittle. The crop is harvested and dried and the onions are ready for use or storage. The crop is prone to attack by a number of pests and diseases, particularly the onion fly, the onion eelworm, and various fungi which can cause rotting. Some varieties of A. cepa, such as shallots and potato onions, produce multiple bulbs. Onions are cultivated and used around the world. As a food item, they are usually served cooked, as a vegetable or part of a prepared savoury dish, but can also be eaten raw or used to make pickles or chutneys. They are pungent when chopped and contain certain chemical substances which may irritate the eyes.
No narrative description available for this taxon yet.
Size & morphology11
Life cycle & reproduction15
Diet & foraging2
Habitat & environment12
Physiology & chemistry3
Other traits1
Compounds documented for Allium cepa across natural-product and food-composition databases — not just the ~150 nutrients on a classic label ("nutritional dark matter").
Compound class profile5 classes
Documented compounds6 636 total
| Compound | Class | Amount | Source |
|---|---|---|---|
| WATER | 922,000 ppm | DukesPhytochem | |
| CARBOHYDRATES | 798,000 ppm | DukesPhytochem | |
| LINOLEIC-ACID | 590,600 ppm | DukesPhytochem | |
| FRUCTOSAN | 400,000 ppm | DukesPhytochem | |
| POLYSACCHARIDES | 400,000 ppm | DukesPhytochem | |
| OLEIC-ACID | 292,900 ppm | DukesPhytochem | |
| PROTEIN | 231,000 ppm | DukesPhytochem |
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Allium cepa has left across the world's sequence archives.
At a glance
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
The complete instruction manual Allium cepa carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Genome sizehow big the whole instruction manual is
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
2n 16105×GoaT · Kew Plant DNA C-values Database · CCDB · ita-fl · CCDB · slov-fl +14
2n 245×CCDB · mediterranean · CCDB · ipcn-api-dl · CCDB · book-ipcn73-74 +1
2n 321×CCDB · ita-fl
n 88×CCDB · ipcn-api-dl · CCDB · book-ipcn75-78 · CCDB · book-ipcn73-74 +1
n 61×CCDB · ipcn-api-dl
diploid1×GoaT · Kew Plant DNA C-values Database
diploid inferred1×PloiDB · genus-scale
Sequencing statusassembly quality — how far to trust these numbers
Assembly level tells you how finished the sequence is — from fragmented contigs, through scaffolds, up to a full chromosome-level assembly. BUSCO % estimates completeness: the share of genes expected to be present that were actually found. These describe the data quality, not the organism.
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
Record type6 190 records
Origin
Range
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Cultivated / Captivenot free-living
A living individual in a botanical garden, zoo or nursery — cultivated or kept, not free-living.
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Holding institutions86 of 162 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
| Institution | Specimens |
|---|---|
| HUN003location not on record | 201 |
| ESP026location not on record | 133 |
| POL003location not on record | 111 |
| ESP027location not on record | 111 |
| GBR006location not on record | 108 |
| Uniwersytet Wrocławskilocation not on record | 27 |
| Philadelphia, US | 21 |
| Durango, MX | 21 |
| ROM007location not on record | 20 |
| UChlocation not on record | 18 |
| Stadt Seeland, Ortsteil Gatersleben, DE | 14 |
| BIO-UNIPIlocation not on record | 14 |
| LDlocation not on record | 13 |
| SLU Artdatabankenlocation not on record | 13 |
| Hazara Universitylocation not on record | 10 |
| Oskarshamn, SE | 9 |
| GBS RAN - Glavny Botanichesky Sad Rossijskoj Akademii Nauklocation not on record | 9 |
| Chongqing Museumlocation not on record | 9 |
| Saint Louis, US | 9 |
| Görlitz, DE | 8 |
| Puerto Ayora, EC | 8 |
| Stockholm, SE | 8 |
| Mérida, MX | 8 |
| KMNlocation not on record | 8 |
| Allentown, US | 7 |
| AZE015location not on record | 7 |
| Mexico City, MX | 6 |
| Chapingo, MX | 6 |
| Moscow State Universitylocation not on record | 6 |
| HRV044location not on record | 6 |
| MeiseBGlocation not on record | 6 |
| Leiden University Medical Centerlocation not on record | 5 |
| Olocation not on record | 5 |
| Karlsruhe, DE | 5 |
| Bronx, US | 4 |
| Baroda, IN | 4 |
| Uniwersytet Warszawskilocation not on record | 4 |
| Jaén, ES | 4 |
| Auckland, NZ | 4 |
| Jyväskylä, FI | 4 |
| San Luis Obispo, US | 4 |
| Tartu, EE | 3 |
| Puebla, MX | 3 |
| Riverside, US | 3 |
| Ann Arbor, US | 3 |
| Barcelona, ES | 3 |
| Beijing, CN | 3 |
| Christchurch, NZ | 3 |
| University of Stellenboschlocation not on record | 3 |
| Helsinki, FI | 3 |
| National Biodiversity Institute, Costa Ricalocation not on record | 3 |
| DBF-NHMDlocation not on record | 3 |
| Guangzhou, CN | 3 |
| Bern, CH | 3 |
| Logan, US | 2 |
| Université de Bordeauxlocation not on record | 2 |
| Podgorica, ME | 2 |
| MAlocation not on record | 2 |
| Museo Entomologico de Leonlocation not on record | 2 |
| CJBGlocation not on record | 2 |
| HNBlocation not on record | 2 |
| Ivano-Frankivsk, UA | 2 |
| Universidad del Quindío (UniQuindío)location not on record | 2 |
| Provincia di Livornolocation not on record | 2 |
| Tuxtla Gutiérrez, MX | 2 |
| AZE014location not on record | 2 |
| Universidade da Região de Joinville - Univillelocation not on record | 2 |
| Philadelphia, US | 2 |
| Dresden, DE | 2 |
| UNESClocation not on record | 2 |
| Ypsilanti, US | 2 |
| Blumenau, BR | 2 |
| Mexico City, MX | 2 |
| Porrentruy, CH | 2 |
| Tsukuba, JP | 2 |
| Stockholm, SE | 2 |
| inatura Erlebnis Naturschau GmbHlocation not on record | 2 |
| Tlalnepantla, MX | 2 |
| Vancouver, CA | 2 |
| Zhengzhou, CN | 2 |
| ASUlocation not on record | 2 |
| Museo naturalistico del Frignano Ferruccio Minghellilocation not on record | 2 |
| Criciúma, BR | 2 |
| Madison, US | 2 |
| Wlocation not on record | 2 |
| San Diego, US | 2 |
| ESP198location not on record | 2 |
| Universidad de Antioquia (UdeA)location not on record | 2 |
| Entomological Society of Latvialocation not on record | 2 |
| Mérida, MX | 2 |
| Bourges, FR | 2 |
| Tilburg, NL | 2 |
| Burlington, US | 2 |
| Vitoria, ES | 2 |
| South Kensington, GB | 2 |
| Canadian Department of Agriculturelocation not on record | 2 |
| Pullman, US | 2 |
| Universidad Católica de Oriente (UCO)location not on record | 1 |
| College Park, US | 1 |
| Davis, US | 1 |
| BDBClocation not on record | 1 |
| Ojo, NG | 1 |
| Royal Alberta Museumlocation not on record | 1 |
| Guasave, MX | 1 |
| San Francisco, US | 1 |
| Irkutsk State Universitylocation not on record | 1 |
| TROMlocation not on record | 1 |
| Aarhus, DK | 1 |
| UTPLlocation not on record | 1 |
| Muzaffarabad, PK | 1 |
| Finnish Museum of Natural History, Botanical Museumlocation not on record | 1 |
| Universidade Federal de Juiz de Foralocation not on record | 1 |
| Universiti Sains Malaysialocation not on record | 1 |
| US | 1 |
| Universidad de Caldas (UCaldas)location not on record | 1 |
| Instituto de Investigaciones Biológicas, Universidad Veracruzana, Región Xalapalocation not on record | 1 |
| WTUlocation not on record | 1 |
| Uniwersytet Marii Curie-Skłodowskiejlocation not on record | 1 |
| Brisbane, AU | 1 |
| Wuhan, CN | 1 |
| Xian, CN | 1 |
| Berlin, DE | 1 |
| Mississippi State, US | 1 |
| Tallinn, EE | 1 |
| BFLlocation not on record | 1 |
| Wuzhou, CN | 1 |
| Weymouth Woods Sandhills Nature Preservelocation not on record | 1 |
| Adelaide, AU | 1 |
| Clemson, US | 1 |
| Granada, ES | 1 |
| Fullerton, US | 1 |
| Ciudad de México, MX | 1 |
| Trondheim, NO | 1 |
| Appalachian State Universitylocation not on record | 1 |
| GZUlocation not on record | 1 |
| JBSlocation not on record | 1 |
| Corrientes, AR | 1 |
| Buenos Aires, AR | 1 |
| Universidad Autónoma de Nayaritlocation not on record | 1 |
| Salvador, BR | 1 |
| CICYTEXlocation not on record | 1 |
| College of the Atlantic, Museumlocation not on record | 1 |
| Wuhan, CN | 1 |
| ICAR-Directorate Of Onion And Garlic Research (DOGR)location not on record | 1 |
| Herbario Selva Central Oxapampa - estación biológica del Jardín Botánico de Missourilocation not on record | 1 |
| Natural History Museum, Tribhuvan Universitylocation not on record | 1 |
| SNSNMClocation not on record | 1 |
| Antiguo Cuscatlán, SV | 1 |
| Quito, EC | 1 |
| Porto Alegre, BR | 1 |
| Herbario MAT de la Universidad Politécnica Estatal del Carchilocation not on record | 1 |
| Universidad Industrial de Santander (UIS)location not on record | 1 |
| GB | 1 |
| Tromso University Museumlocation not on record | 1 |
| Portland, US | 1 |
| Williamsburg, US | 1 |
| URCAlocation not on record | 1 |
| UNIVILLElocation not on record | 1 |
| Centro de Investigación en Biodiversidad y Conservación, Universidad Autónoma del Estado de Moreloslocation not on record | 1 |
| San Jose State University, Museum of Birds and Mammalslocation not on record | 1 |
| València, ES | 1 |
| Universidad Nacional de Colombia (UNAL)location not on record | 1 |
Cultivated / Captivenot free-living
A living individual in a botanical garden, zoo or nursery — cultivated or kept, not free-living.
Where the DNA of Allium cepa was picked up in samples of water, soil or air — nobody saw the organism, only its DNA left behind. A trace is a clue that the species was near, not a confirmed sighting.
Signal
Where its DNA was found
How strong is each trace?
Modelled climatemodelled
How to read this: each dot is one detection of this species' DNA in an environmental sample. The confidence meter weighs how many independent studies and places back up the signal — one detection in one study is a hint; many across several studies is solid. Records dated before 2008 (when eDNA methods began) are treated as likely mislabeled and left off the map.