ALLIUM, a very extensive genus of bulbous Monocotyledonous plants, belonging to the natural order Liliacece. The species are all remarkable for having, in a greater or less degree, the odour of garlic, and for the agreeable stimulating effects that accompany it. For this reason some of them have been objects of cultivation from the highest antiquity.
As a genus, Allium is known among other Llliacem, by the flowers growing in round heads or umbels, by the perianth being deeply divided into six spreading lobes, and by having a capsule with three angles, three valves, and three cells, sometimes so deeply lobed, as to have the appearance of six cells. The number of species is very considerable ; they are almost exclusively natives of the northern hemisphere, and are principally found wild in the meadows and groves of Europe, in the north of Asia, and the north of Egypt ; a small proportion only inhabiting corresponding latitudes in North America. Many of them are handsome flowering plants, but as they are more important on account of their useful properties, we shall confine ourselves to some account of the kinds commonly cultivated in the kitchen-garden.
Allium Cepa, the Common Onion, is too well known to require description. It is not certain of what country it is a native, but it has from time immemorial been cultivated in Egypt. Its varieties are not very numerous, considering that it is almost exclusively increased by seed : the most remarkable are the Blood-Red Onion, which is the most pungent ; the Strasburg Onion, which is the hardiest; the Silver-Skinned Onion, which is the smallest, and the most fitted for pickling; and the onions of Portugal and Tripoli, which are the largest and the most delicate. In this country the bulbs do not generally arrive at the large size of those imported from Portugal and Spain ; but skilful gardeners have nevertheless succeeded in procuring them fully as fine. Their method has been to take the small onions of a late-sown crop of the previous year, and to plant them in rows in the beginning of April, laying them on the surface of the soil, each surrounded with about a handful of decayed and nearly dry manure. All the time that is usually lost in seed sowing is thus avoided, and the moment the bulbs push forth new roots, they find themselves in the midst of an abundant store of food, which continues to supply them with nutrition during the whole of the growing season. As they advance in size, the soil round
the bulbs is frequently disturbed by the hoe, for the sake of exposing as much as possible the carbonaceous matter Qf the manure to the action of the atmosphere. This process is only discontinued when the leaves begin to turn yellow; the bulbs are then allowed to ripen as usual.
Allium schmnoprasum, the Chive, is a little tufted plant, with slender, cylindrical, taper-pointed, dark-green leaves; its flowers are arranged in a small compact round head, and are of a purplish or pale violet colour ; the bulbs are small, long, and white, and grow in dense, matted tufts. It is a native of the mountainous regions of Europe, from Lapland to Italy ; and is found here and there in Great Britain. It is more employed by the French for their cookery than in this country.
Allium fistalosum, the Welsh Onion, is a native of Siberia, and is supposed to have gained its English name from having been imported originally from Germany, with the name Walsch, or foreign, attached to it. It is a perennial, and cultivated chiefly for the purpose of being sold in the markets when very young, at which time its flavour is delicate ; its hardiness enables it when young to brave our spring cold better than the common onion.
Aliens Ascalonicum, the Shallot, a native of Asia Minor, is in many respects similar to the chive, from which it is known by its larger leaves, its smaller and more deeply-coloured flowers, and by its stamens having alternately three points on the filaments. It more over produces bulbs of sufficient size to be fit for use, and accordingly, while the leaves only are employed in the chive, the bulbs are the parts sought for in the shallot. These multiply abundantly, so that every year, when the crop is taken up, there is plenty of small bulbs which can be reserved for planting the succeeding season, while the fine fully-formed ones are selected for the kitchen. To obtain the bulbs in the greatest perfection, they should not be buried in the earth, as is the common practice, but merely placed on the surface of the soil.