Allium cepa
onion
Family AmaryllidaceaeAlso called bulb onion, common onion, garden onion, shallot
About
Allium cepa, the onion, is the most widely cultivated species of Allium and a staple vegetable worldwide. Shallots are now treated as a variety of this species.
Care at a glance
- Pet safety
- Toxic to dogs, cats and horses (n-propyl disulfide); can cause vomiting, breakdown of red blood cells, blood in urine and weakness.
- People
- Not recorded.
- Light
- Full sun to light shade. General guidance for the genus
- Water
- Avoid overly damp ground; wet conditions invite bulb rot and other fungal problems. General guidance for the genus
- Soil
- Fertile, loose, well-drained soil; sand or loam both suit. General guidance for the genus
- Mature size
- Typically 15–45 cm tall.
“General guidance for the genus” marks advice sourced for the genus as a whole rather than this species.
Field notes
Morphology
A biennial usually grown as an annual, 15–45 cm tall. Hollow, fleshy, bluish- to yellowish-green leaves grow in a flat fan from a basal plate; food stored in the leaf bases swells into the bulb, whose outer scales dry to a papery skin in autumn.
Distribution & habitat
Known only from cultivation; its wild ancestor is unknown, though escapes have established in some regions.
Cultivation notes
Grown in yellow or brown (sweet, good for caramelising), red or purple (sharp, often eaten raw) and white (mild) forms, and used raw, cooked, pickled and in dishes such as French onion soup.
History & etymology
Formally described by Carl Linnaeus in Species Plantarum in 1753. The shallot, once A. ascalonicum, was merged into this species.
Habitat
- Altitude
- Not recorded
- Altitude class
- —
Cultivation
- Difficulty
- easy
Text adapted from Wikipedia, CC BY-SA 4.0.
Crossed A. cepa with another species?Register the cross. If it's not documented yet you'll be the first contributor; if someone already registered it, you'll be taken there to add your photo.