336. The procuring of fresh seed is a matter of im portance ; for if it be kept over a year, a great part will not germinate. Onion seed can be ripened in our climate ; but some how or other it is very apt to degenerate. A good deal, however, is yearly saved in the neighbourhood of Deptford. Imported seed is always proved by attentive gardeners, and also by seedsmen: a small sample being sown in a flower-plot, and placed in a hot-house, the qua lity, as far as capability of germination is concerned, is soon determined. When it is intended to collect home seed, some of the firmest, largest, and best shaped bulbs are selected, and planted out in February or March, in good ground, near a south wall or hedge. When the heads are formed, they are supported by lines of small cord pass ed between stakes. In September, if the season be fa vourable, the seed ripens, turning to a brown colour, and beginning to burst the cells which contain it. The heads are then gathered ; and, when dried, the seeds are beat out, and kept in paper bags.
337. A bulbiferous variety is cultivated in some gar dens, under the name of Tree onion. Its culture has been recommended by Mr George Nicol of Edinburgh, in the Memoirs of the Caledonian Horticultural Society, (vol. i. p. 350.) under the title of .4/lluni Canadense, a species for which it has very generally been mistaken. The stems from two-year old plants rise more than two feet high. Se veral bulbs of different sizes are produced at the top of the stem, and these, as well as the root-bulbs, may be used for kitchen purposes, like common onions. They are of good flavour, though rather stronger in taste thari common onions. They are well adapted for keeping, and especially for pickling. Mr Nicol observes, that they are very sel dom infested by maggots ; and he recommends, therefore, that a few stock-bulbs should be preserved in gardens, to provide against the contingency of the crop of common onions failing.
This bulb-bearing or tree-onion is figured in the a Bo tanical Magazine," plate 1469, and described by Dr Sims as merely a variety of the 41/1um cepa. It is certainly not the ?illium Canadense of wiltdenow 0,Pursh, (for which, as already noticed, it has been generally the Ca nadian plant having flat linear leaves, and a slender unin flated stern, with top-bulbs resembling those of garlie. But, on the other hand, it differs from the common Onion, not only in producing bulbs at top, but in having a stronger alliaceous flavour, and in being perennial. Possibly there fore it might constitute a distinct species.
338. The Egyptian onion, or Ground onion, has been considered as another variety of Allium cella, but seems to be more nearly allied to ?. fistulosunz. Instead of pro
ducing bulbs at the top of the stem like the former, this plant produces clusters at the surface of the ground in the manner of potatoes. It was brought from Egypt, it is be lieved, during the occupation of that country by the British army, and was first cultivated in the neighbourhood of Edinburgh in 1811, by Lieutenant Burn of the Royal Navy. The bulbs are planted in April, at a foot or sixteen inches asunder, and covered with earth only about half an inch deep. In the course of the season, a number of bulbs form in clusters around the parent bulb, as already de scribed ; those nearest the surface grow largest ; those to ward the centre arc soonest ripe, and may be removed, to give room to the others. If intended for keeping, they should he taken up before they attain maturity. If allowed to remain long in the ground, they sometimes become of a very large size. The bulb seems quite hardy, having been observed to brave the severity of frosty weather, at least equally. well as the common onion. Flower stems rise sparingly, and only from strong bulbs. In quality the ground onion seems not inferior to the common onion. it more speedily reaches maturity, being planted in April, and reaped in August and September. Maggots have not been observed to infest it ; but it has not been ascertained that they will not attack it. From our own experience, we suspect that it will speedily degenerate in this country.
539. The scallion seems to be a third variety of the AI bum Cepa, distinguished by the circumstance of its never forming a bull) at the root. Miller states, that the scallion is propagated by parting the roots in autumn; that it grows in almost any soil or situation, and resists our severest win ters. He adds, that, being green and fit for use very early in the spring, it is worthy of a place in all good kitchen gardens. It was, indeed, formerly much in use ; but the true scallion is now very little known, and is said to exist only in a few gardens, where it is preserved by way of cu riosity. Some derive the name scallion, or escallion, from ascalonicunz, and without more ado identify it with the ro cambole, ascalonicunz); others consider it as synony mous with the Welch onion, (A. fzstzdosum); but both these species were well known to Mdler, and accurately distinguished by him, and yet he describes the scallion as something different. In popular language, scallion means sometimes a thick-necked seedling onion, drawn for use in the green state ; and sometimes, as already mentioned, a winter kept onion which has sprouted, and is planted for some weeks in the spring till it acquire green leaves.