Allium cepa L.
|Malaysia||Bawang merah, bawang kecil, bawang besar|
|English||Onion, common onion, shallot onion|
|Indonesia||Bawang merah, bawang beureum, bawang bombay|
|Papua New Guinea||Lip anian, anian (Pidgin)|
|Philippines||Sibuyas tagalog (Tagalog), bauang pula (Tagalog),lasona (Iloko)|
|Cambodia||Khtüm krâhââm, khtiim barang|
|Laos||Hoom bwàx, bwàx fàlangx|
|Thailand||Horn farang, horn hua yai (central)|
|Vietnam||H[af]nh t[aa]y, h[af]nh c[ur], h[af]nh t[aw]m|
This plant probably originated from central Asia, but nowhere truly wild. Cultivated all over the world; cultivar (cv.) group Aggregatum (shallot) predominates in the tropical lowland of South-East Asia, but cv. group Common Onion is grown in the Philippines, Papua New Guinea and Thailand.
It is a biennial herb that is grown as an annual, up to 100 cm tall. The mature bulb can grow up to 15 cm in diametre.
The leaves are semiterete form, solid at first but later becoming hollow and pale bluish-green. Margin is terete. It is often inflated and hollow in the middle or in the lower part.
Inflorescence is up to 2000 flowers. The tepals are greenish-white to purplish. The stamens are sometimes slightly exceeding tepals, style shorter than stamens at anthesis.
The fruit is 4-6 mm in diametre, containing up to 6 seeds. The size of seeds is about 3 mm x 2 mm. In cv. group Common Onion the bulbs are large and normally single, and the plants reproduce from seed or from seed-grown bulbils, while in cv. group Aggregatum (shallot) the bulbs are smaller, several to many forming an aggregated cluster and reproduce vegetatively via lateral bulbs.
Tropical shallot requires an average day temperature of 20-26°C and a day-length of at least 11 hours, whereas common onion prefers slightly lower temperatures and a day-length of at least 13 hours. In Indonesia, shallot is mainly grown in the lowlands below 450 m altitude, preferably on well-drained alluvial clay soil. Whereas Chinese chives, welsh onion and garlic are grown in the highlands up to 2200 m altitude. Most tropical onions are grown during the dry season, as too much rain will result in a high incidence of fungal diseases. They require well-drained soils.
Plant Resources of South-East Asia No 12(1). 1998.