The species and varieties belonging to this genus are among tie gayest and most easily cultivated of our winter and early spring flowering plants; producing, with ordinary management, an abundance of bright-colored, cheerful-looking flowers for some three months in succession; and for amateurs, having only a small collection of plants, nothing could be more useful.

Beginners should commence with young plants, of O. racemous for instance, which, if procured at once, will form nice little specimens for blooming in spring; they should be placed in a cold frame, or a cool airy part of the greenhouse, giving them plenty of water at the root, syringing them overhead on the mornings and evenings of bright days, and keeping them near the glass, to induce close short-jointed growth. If the pots are found to be well filled with roots, which, in the case of healthy plants received from the nursery, will be sure to be the case, give a liberal shift, say into pots two sizes larger than those in which they have been growing For soil use about equal parts of good rich light turfy loam, and strong fibry peat, broken up so that it would pass through a half-inch mesh sieve, and well intermixed with sharp sand, and some lumpy bits of charcoal, to keep the mass open after the decay of the fibre. Care should be observed to thoroughly drain the pots, for the plants will be found to require a very liberal supply of water; and unless perfect drainage is secured, the soil will be apt to become sour towards the bottom of the pots.

Beyond the ordinary roatine of watering, syringing, etc, very little attention will be necessary during the growing season; but if spider should make its appearance, no time must be lost in eradicating it, by laying the plants on a clean mat and thoroughly washing the under sides of the leaves with the syringe; this operation repeated twice a week for a fortnight, will generally be successful, unless when the plants are growing jn too warm a situation, and in this case it will be nearly impossible to keep them free from this pest If any branch is observed to be taking a decided leave of its fellows, it should be stopped, and the main shoot should be kept neatly tied to a stake; this is supposing that the object is to obtain a well furnished pyramidal bush, which is decidedly the best method of training; but if any other form is desired, it will be easily attained by timely attention; for the plants, being vigorous growers, are easily trained, with a little care, in any shape. If the plants can be kept near the glass in a light airy situation, so as to induce short compact growth, they may be kept growing till late in antumn, but they should not be kept too close at this season.

They may be wintered in a cold pit or wherever they can be protected from damp, for a few degrees of frost will not injure them. After they have bloomed in spring allow them to stand in a rather cool place for a fortnight, then cut in the shoots slightly, and place them in a moist and rather close spot, to induce the buds to break freely, and when the young shoots are about an inch long, re-pot, giving a liberal shift, using the same soil, etc, as already recommended, syringing freely until the roots get hold of the fresh soil When this is the case they situation out of doors, where they will not be exposed to the midday ran. Here they will grow freely and will not be bo liable to be infested with red spider as in the greenhouse.

With a little attention it is easy to hare these plants in bloom at almost any time during the winter, but to effect this they ought to be started into growth sufficiently early to allow of having the young wood firm by the middle of September, after which time the plants should be freely exposed to the sun, and not over watered at the root. Treated in this way they will commence flowering immediately they are placed in a moderately warm greenhouse, and if supplied with manure water they will bloom profusely for a long time in succession. When the specimens become too large to be conveniently re-potted every season, supply them liberally with manure water while making their wood and blooming, which will preserve them in sufficient vigor for several seasons; or they may be slightly disrooted every year, re-potting them in the same sized pots, and using very rich soil - Alpha, in Gardeners' Chronicle.

Spirea Grandivlora, Hooker

Spirea Grandivlora, Hooker in Bot Mag., t. 4795; alias Amelanchier bacemosa, Lindl. in Bot Rog., 1847, sub. t 88. - A very remarkable hardy shrub, found by Mr. Fortune in the North of China, and sent home as an Amelanchier, which it is much like in habit, except that its flowers are as large as a Philadelphia. The leaves are thin, alternate, lanceolate, entire, and apiculate. The flowers are from two to six on a raceme, white or cream colored, with a serrated petaloid calyx, and a great fleshy green disk, in the centre of which stand five free carpels. Some of the flowers are male, and it was an examination of one of these which led to the surmise that the plant might be, what it is very like, and what Mr. Fortune called it, an Amelanchier. - Living specimens have enabled Sir Wm. Hooker to show that this cannot be, and he refers the plant to Spiraea. That the fruit, when it is produced, will show the plant to be neither the one nor the other, we cannot doubt In the meanwhile we leave it with its latest name. It is a very handsome plant, forming, when wild, a small bush; and if it should prove hardy, which is probable, it would be a groat acquisition. - Gard. Chronicle.