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Allium cepa L.

Family Name: Amaryllidaceae
Common Name: Onion, Common Onion, 洋葱, 葱头
Full Sun: 6-8h Moderate Water Fruit & Vegetable Herb & Spice Annual Grass & Grass-like Plant


Family Name
Genus Epithet
Species Epithet
Name Authority
Name Status (botanical)
Common Names

Classifications and Characteristics

Plant Division Angiosperms (Flowering Seed Plants) (Monocotyledon)
Plant Growth Form Grass & Grass-like Plant
Lifespan (in Singapore) Biennial, Annual
Mode of Nutrition Autotrophic


Native Distribution The true wild A. cepa plants are unknown. The earliest onion depictions originated in Egypt and date back to about 2700BC.
Native Habitat Terrestrial
Preferred Climate Zone Sub-Tropical / Monsoonal
Local Conservation Status Exotic (Horticultural / Cultivated Only)

Description and Ethnobotany

Growth Form Biennial herb.
Roots Shallow, fibrous roots grow up to 30 cm long and spread radially about 30 cm from the stem. 
Foliage Linear leaves are arranged in a small, erect cluster. Young leaves are initially solid, later becoming hollow and cylindrical (up to 50 cm long).
Flowers Greenish white to purple flowers are arranged in ball-shaped, 2-8 cm wide clusters, known as umbels. Each umbel is composed of 50-2000 flowers.  
Fruits Dry, dehiscent fruits are known as capsules (4-6 mm wide). They contain black, wrinkled seeds.
Cultivation This species is not typically grown in countries located near the equator, because it typically does not produce viable seed in such climates and is sensitive to heavy rains.  
Ethnobotanical Uses Edible Plant Parts (Edible Storage Organs)
Food (Fruit & Vegetable : The bulb is used as an ingredient in various hearty warm dishes. They are used raw in cold salads, pickling, cooking and frying.;Herb and Spice)
Medicinal ( In folk medicine, onions are used as a diuretic.)

Plant Care and Propagation

Light Preference Full Sun
Water Preference Moderate Water
Propagation Method Storage Organ (Bulb), Division


Mature Foliage Colour(s) Green
Mature Foliage Texture(s) Smooth
Foliar Type Simple / Unifoliate
Foliar Arrangement Along Stem Alternate
Foliar Shape(s) Non-Palm Foliage (Linear)
Foliar Venation Parallel
Foliar Apex - Tip Acute

Floral (Angiosperm)

Flower Colour(s) White
Flower Grouping Cluster / Inflorescence
Flower Location Terminal
Inflorescence Type Compound Umbel

Image Repository



Master ID 31532
Species ID 5931
Flora Disclaimer The information in this website has been compiled from reliable sources, such as reference works on medicinal plants. It is not a substitute for medical advice or treatment and NParks does not purport to provide any medical advice. Readers should always consult his/her physician before using or consuming a plant for medicinal purposes.
Species record last updated on: 25 August 2021.