GRAFTING

In Horticulture, the operation of affixing one portion of a plant to another in such a manner as that a vital union may take place between them. Grafting may be performed both with herbaceous and ligneous plants; but in practice it is chiefly confined to the latter, and more especially to the propagation of esteemed varieties of fruit trees. A gratted plant consists of two parts: the stock or stem, which is a rooted plant fixed in the ground; and the scion, sometimes, but erroneously, termed the graft, which is a detached portion of another plant to be affixed to it. The operation of grafting can only be performed within certain physiological limits; but what these are science has not yet absolutely determined. ' In general, all the species of one genus may be grafted on one another reciprocally; but this is not universally the case, because the apple cannot be grafted on the pear, at least not for any useful purpose. In general, it may be presumed that all the species of a natural order, or at least of a tribe, may be grafted on one another; but this does not hold good universally. The reverse of this doctrine, however, viz. that the species belonging to different natural orders cannot be grafted on one another, holds almost universally true; and therefore a safe practical conclusion is, that in choosing a stock the nearer in affinity the species to which that stock belongs is to the scion the more certain will be the succe . Grafting is one of the most important operations in horticulture, as affording the most eligible means of multiplying and perpetu.iting all our best varieties of fruit trees, and many kinds of trees and shrubs not so con GRAM IN ACE.E. veniently propagated by other means. Varieties of fruits are originally procured by selection from plants raised from seed, but they can only be perpetuated by some mode which continues the individual; and though this may be done by cuttings and layers, yet by far the most eligible mode is by grafting, as it produces stronger plants in a shorter time than any other methods. Grafting is performed in a great many different ways, but the most eligible for ordinary purposes is what is commonly call?d splice grafting, or whip grafting. In executing this mode both the scion and the stock are pared down in a slanting direction; afterwards applied together, and made fast with strands of bast matting, in the same manner as two pieces of rod are spliced together to form a whip handle. To insure succe , it is e entially nece ary that the alburnum or inner bark of the scion should coincide accurately with the inner bark of the stock; because the vital union is effected by the sap of the stock rising up through the soft wood of the scion. After the scion is tied to the stock, the graft is said to be made; and it only remains to cover the part tied with a ma of tempered clay, or any convenient composition that will exclude the air. The season for performing the operation is, for all deciduous trees and shrubs, the spring, immediately before the movement of the sap. The spring is also the most favourable season for evergreens; but the sap in this cla of plants being more in motion during winter than that of deciduous plants, grafting, if thought nece ary, might be performed at that season. Grafting by approach, or inarching, is a mode of grafting, in which, to make sure of succe , the scion is not separated from the parent plant till it has become united with the stock. For this purpose the stock and the plant containing the scion must be growing close together; and the scion being drawn to one side, and made to approach the stock, is spliced to it by cutting off a portion of its bark and wood, and a similar portion of the bark and wood of the stock, applying the one to the other so that their alburnums may joiii, and then making both fast by matting, and excluding the air by clay, grafting wax, or mo . When the scion has effected a vital union vfith the stock, its lower extremity is cut through, so as to separate it from the parent plant, and it now becomes an independent graft. In this way trees of difficult propagation may be propagated with certainty; while if any of the other modes of propagation, whether by cuttings or grafting, were adopted, a proportion of the cuttings or scions would, in all probability, be lost. Grafting herbaceous plants differs in nothing from grafting such as are of a woody nature, excepting that the operation is performed when both stock and scion are in a state of vigorous growth. Grafting herbaceous plants is but little practised in England, and on the Continent chiefly as a matter of amusement. The only useful purpose to which it has hitherto been applied is that of grafting the finer kinds of dahlias on tubers of the more common and vigorous growing sorts. In the Paris gardens the tomato is sometimes grafted on the potato, the cauliflower on the borecole, and one gourd on another, as matter of curiosity. Grafting the herbaceous shoots of voody plants— the greffe herbace of the French — is scarcely known among English gardeners; but it has been extensively employed by French nurserymen, and even in some of the ro)' , stilts.) The Linn a ean name of the order of long-legged wading birds. GRAMINACE^. An order of Endogenous plants, commonly called gra es, in which the parts of fructification are e entially perfect, although they are in a very unusual state in what may be called their acce ory organs. They have neither calyx nor corolla; but, in lieu of them, imbricated scales, called palcae and glumes: the latter of which give rise to the name glumaceous, often applied to these plants. They are nearly allied to sedges, from which they differ in having the sheaths of their leaves slit and their stems hollow. Corn of all kinds, the bamboo, the sugar-cane, many kinds of pasture plants, and reeds, belong to different species of Graminacece. Ergot is the ovary of rye attacked by a fungus called Ergot at i a aborlans. The flinty surface of the stems or straw renders many valuable for domestic use, as for forming the plat from which straw bonnets, . are [s. 535]