The tree onion (''Allium'' × ''proliferum'') is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

plant similar to the common onion (''A. cepa''), but with a cluster of bulblets where a normal onion would have flowers. Tree onions are also known as topsetting onions, walking onions, or Egyptian onions. Genomic evidence has conclusively shown that they are a

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

hybrid of the

shallot The shallot is a botanical variety (a cultivar) of the onion. Until 2010, the (French red) shallot was classified as a separate species, ''Allium ascalonicum''. The taxon was synonymized with ''Allium cepa'' (the common onion) in 2010, as the d ...

and the

Welsh onion ''Allium fistulosum'', the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar ...

(''A. fistulosum''). However, some sources may still treat the tree onion as ''A. cepa'' var. ''proliferum'' or ''A. cepa'' Proliferum Group. Tree onion bulblets will sprout and grow while still on the original stalk. The bulblets are usually marble-sized, between 0.5 cm to 3 cm in diameter. They may bend down under the weight of the new growth and take root some distance from the parent plant, giving rise to the name "walking onion". It has been postulated that the name "Egyptian onion" derived from

Romani people The Romani (also spelled Romany or Rromani , ), colloquially known as the Roma, are an Indo-Aryan ethnic group, traditionally nomadic itinerants. They live in Europe and Anatolia, and have diaspora populations located worldwide, with sig ...

bringing tree onions to Europe from the Indian subcontinent. The phenomenon of forming bulblets (

bulbil A bulbil (also referred to as bulbel, bulblet, and/or pup) is a small, young plant that is reproduced vegetatively from axillary buds on the parent plant's stem or in place of a flower on an inflorescence. These young plants are clones of the pa ...

s) instead of flowers is also seen in top-setting

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Allium fistulosum, Welsh onion and Allium chinense, Chinese onion. It is native to South A ...

and other alliums, which sometimes may also be referred to as top onions or tree onions. Also known as turfed stone leek, it may be cultivated commercially and for foliage. It is described as a shallot which can be grown in tropical conditions. Many tree onions are very strong flavoured, although some cultivars are relatively mild and sweet. The underground bulbs are particularly tough-skinned and pungent, and can be quite elongate, like

leek The leek is a vegetable, a cultivar of ''Allium ampeloprasum'', the broadleaf wild leek ( syn. ''Allium porrum''). The edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. The genus ''Alli ...

s, or in some types may form bulbs up to 5 cm across. Young plants may be used as

scallion Scallions (also known as spring onions or green onions) are vegetables derived from various species in the genus ''Allium''. Scallions generally have a milder taste than most onions and their close relatives include garlic, shallot, leek, ch ...

s in the spring, and the bulblets may be used in cooking similarly to regular onions, or preserved by

pickling Pickling is the process of preserving or extending the shelf life of food by either anaerobic fermentation in brine or immersion in vinegar. The pickling procedure typically affects the food's texture and flavor. The resulting food is called a ...

Culinary use

Japan

The plant is known as in Japan. Considered a specialty of the

Hiroshima Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Hiroshima Prefecture has a population of 2,811,410 (1 June 2019) and has a geographic area of 8,479 km² (3,274 sq mi). Hiroshima Prefecture borders Okayama ...

, it is used in local cooking similar to other scallions.

Korea

In Korea, ''Allium'' × ''proliferum'' along with '' A. fistulosum'' is called ''pa'' (, "scallion"), while common

onion An 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 ...

s are called ''yangpa'' (, "Western scallion"). While ''A.'' × ''proliferum'' is called ''jjokpa'' (), ''A. fistulosum'' is called either ''

daepa ''Allium fistulosum'', the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar ...

'' (, "big scallion") or ''

silpa ''Allium fistulosum'', the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar ...

'' (, "thread scallion") depending on the size. Unlike ''daepa'' and ''silpa'', which are usually used as a spice, herb, or garnish, ''jjokpa'' is often used as the main ingredient of various scallion dishes in

Korean cuisine Korean cuisine has evolved through centuries of social and political change. Originating from ancient agricultural and nomadic traditions in Korea and southern Manchuria, Korean cuisine reflects a complex interaction of the natural envi ...

. Common dishes made with ''jjokpa'' include ''

pajeon ''Pajeon'' (, ) is a variety of '' jeon'' with scallion as its prominent ingredient, as ''pa'' () means scallion. It is a Korean dish made from a batter of eggs, wheat flour, rice flour, scallions, and often other ingredients depending on the va ...

'' (scallion pancakes) and ''

pa-kimchi Pa-kimchi (), also known as green onion kimchi or scallion kimchi, is one of types of Kimchi that Koreans usually eat for banchan (traditional side dishes) and is most popular in Jeolla-do. Pa Kimchi uses medium-thick green onions known as ''jjok ...

'' (scallion kimchi). File:Haemulpajeon.jpg, '' Haemul-

'' (scallion pancake with seafood) File:Scallion kimchi.jpg, ''

Pa-kimchi Pa-kimchi (), also known as green onion kimchi or scallion kimchi, is one of types of Kimchi that Koreans usually eat for banchan (traditional side dishes) and is most popular in Jeolla-do. Pa Kimchi uses medium-thick green onions known as ''jjok ...

'' (scallion kimchi)

Gallery

Image:Allium cepa2.jpg, Egyptian onions Image:Sint Jansui (Allium fistulosum var. bulbifera).jpg, Tree onion Image:Egyptian Tree Onion, Walking Onion, Topset Onion (Allium cepa var. proliferum).jpg, Growing in a garden

References

{{taxonbar, from=Q41794154 proliferum Interspecific plant hybrids Korean vegetables Onions Perennial vegetables

Culinary use

Japan

Korea

Gallery

See also

References