Allium x proliferum
|Allium x proliferum subsp. var.||Tree onion, Top Onions, Topset Onions, Walking Onions, Egyptian onions|
Tree onions are a strong-growing onion with a bunch of bulblets where a normal onion would have flowers.
Their species name is "proliferum", although they have many characteristics of the Allium cepa, and are also commonly called Top Onions, Topset Onions, Walking Onions, or Egyptian onions. Tree Onion 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. Recent research has shown that the tree onion may be a cross between Allium cepa, the cultivated onion, and Allium fistulosum, the Welsh onion (Some sites may currently treat the Tree Onion 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. Bulblets in tree onions are generally very small, usually within .5 cm to 3 cm in diameter, although sizes may differ out of this range, from time to time. A similar relative to the tree onion is the pearl onion and a few other, nameable varieties.
Pests and diseases
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963