Tree onion
1123038
225511228
2008-07-14T02:03:23Z
96.228.232.240
{{Taxobox
| name = Onion
| image = Onions.jpg
| image_width = 240px
| image_caption = Onions
| regnum = [[Plant]]ae
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Monocotyledon|Liliopsida]]
| ordo = [[Asparagales]]
| familia = [[Alliaceae]]
| genus = ''[[Allium]]''
| species = '''''A. cepa'''''
| binomial = ''Allium cepa''
| binomial_authority = [[Carolus Linnaeus|L.]]
| subdivision_ranks = horticultural group
| subdivision = Proliferum Group
}}
'''Tree onions''' are a strong-growing [[onion]] with a bunch of bulblets where a normal onion would have flowers.
They are members of the "proliferum" cultivar of the onion (''Allium cepa''), and are also commonly called '''Top Onions''', '''Topset Onions''', '''Walking Onions''', or '''Egyptian onions'''. In some varieties these bulblets will sprout and grow while still on the original stalk, which may bend down under the weight of the new growth, giving rise to the name, '''walking onion'''. While these onions are often listed as ''Allium cepa'' var. ''proliferum'', recent research has shown that the tree onion is a cross between ''Allium cepa'', the cultivated [[onion]], and ''Allium fistulosum'', the [[Welsh onion]]. The [[Royal Horticultural Society]] currently treats it as ''Allium cepa'' Proliferum Group. This phenomenon of forming bulblets instead of flowers is also seen in [[garlic]] and other various wild species of ''[[Allium]]''. A similar relative to the tree onion is the [[pearl onion]].
<gallery>
Image:Allium fistulosum bulbifera0.jpg|Tree onions
Image:Allium cepa2.jpg|Egyptian onions
Image:Sint Jansui (Allium fistulosum var. bulbifera).jpg|Tree onion 9 april 2007
Image:Egyptian Tree Onion, Walking Onion, Topset Onion (Allium cepa var. proliferum).jpg|Growing wild along a fence
</gallery>
[[Category:Allium]]
[[Category:Onions]]
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