or BUD, in Botany: a compendium or epitome of a plant, seated upon the stem and branches, and covered with scales, in order to defend the tender rudiments enclosed from cold and other external injuries, till, their parts being unfolded, they acquire strength, and render any further protection unnecessary.
Buds, together with bulbs, which are a species of buds generally seated upon or near the root, constitute that part of the herb called by Linnaeus hibernacula; that is, the winter quarters of the future vegetable: a very proper appellation, as it is during that severe season that the tender rudiments are protected in the manner just mentioned.
Plants, considered in analogy to animals, may properly enough be reckoned both viviparous and oviparous. Seeds are the vegetable eggs; buds, living fetuses, or infant plants, which renew the species as certainly as the seeds.
Buds are placed at the extremity of the young shoots, and along the branches, being fixed by a short footstalk upon a kind of brackets, the remainder of the leaves, in the wings or angles of which the buds in question were formed the preceding year. They are sometimes placed single; sometimes two by two, and those either opposite or alternate; sometimes collected in greater numbers in whirls or rings.
With respect to their construction, buds are composed of several parts artificially arranged. Externally, we find a number of scales that are pretty hard, frequently armed with hairs, hollowed like a spoon, and placed over each other like tiles. These scales are fixed into the inner plates of the bark, of which they appear to be a prolongation. Their use is to defend the internal parts of the bud; which, being unfolded, will produce, some, flowers, leaves, and stipulae; others, footstalks and scales. All these parts, while they remain in the bud, are tender, delicate, folded over each other, and covered with a thick clammy juice, which is sometimes resinous and odoriferous, as in the tamarack tree. This juice serves not only to defend the more tender parts of the embryo plant from cold, the assaults of insects, and other external injuries; but likewise from excessive perspiration, which, in its young and infant state, would be very destructive. It is conspicuous in the buds of horse chestnut, poplar, and willow trees.
In general, we may distinguish three kinds of buds; that containing the flower, that containing the leaves, and that containing both flower and leaves.
The first, termed gemma florifera, and by the French bouton à fleur or à fruit, contains the rudiments of one or several flowers, folded over each other, and surrounded with scales. In several trees, this kind of bud is commonly found at the extremity of certain small branches, which are shorter, rougher, and less garnished with leaves, than the rest. The external scales of this species of bud are harder than the internal; both are furnished with hairs, and in general more swelled than those of the second sort. The bud containing the flower too is commonly thicker, shorter, almost square, less uniform, and less pointed; being generally terminated obtusely. It is called by Pliny oculatus gemmeus; and is employed in that species of grafting called inoculation, or budding.
The second species of bud, viz. that containing the leaves, termed gemma foliifera, and by the French bouton à feuilles or à bois, contains the rudiments of several leaves, which are variously folded over each other, and outwardly surrounded by scales, from which the small stipulae that are seated on the foot of the young branches are chiefly produced. These buds are commonly more pointed than the former sort. In the hazel nut, however, they are perfectly round; and in horse chestnut, very thick.
The third sort of bud is smaller than either of the preceding; and produces both flowers and leaves, though not always in the same manner. Sometimes the flowers and leaves are unfolded at the same time. This mode of the flower and leaf bud is termed by Linnaeus gemma foliifera et florifera. Sometimes the leaves proceed or emerge out of this kind of bud upon a small branch, which afterwards produces flowers. This mode of the flower and leaf bud is termed by Linnaeus gemma foliifera florifera, and is the most common bud of any.
Such buds as produce branches adorned only with leaves, are called barren; such as contain both leaves and flowers, fertile. From the bulk of the bud we may often with ease foretell whether it contains leaves only, or leaves and flowers together, as in cherry and pear trees.
Neither the buds produced on or near the root, called by some authors turiones, nor those produced on the trunk, and from the angles or wings of the leaves, contain, in strict propriety, an entire delineation of the plant; since the roots are wanting; and in various
buds, as we have seen, shoots are contained with leaves only, and not with flowers: but as a branch may be considered as a part similar to the whole plant, and, if planted, would in process of revegetation exhibit or produce roots and flowers, we may in general allow, that the bud contains the whole plant, or the principles of the whole plant, which may be unfolded ad libitum; and thus resembles the seed, in containing a delineation of the future plant in embryo: for although the bud wants a radicle, or plumula, of which the seed is possessed, yet it would undoubtedly form one, if planted in the earth. But as the medullary part adhering to the bud is too tender, and by the abundance of juice flowing into it from the earth would be disposed to putrefaction, the buds are not planted in the soil, but generally inserted within the bark of another tree; yet placed so that the production of the marrow, or pith, adhering to them, may be inserted into the pith of the branch in which the fissure or cleft is made; by which means there is a large communication of juice. This propagation by gems or buds, called inoculation, is commonly practised with the first sort of buds above described.
From the obvious uses of the buds, we may collect the reason why the Supreme Author of nature has granted this sort of protection to most of the trees that are natives of cold climates: and, on the other hand, denied it to such as, enjoying a warm benign atmosphere, have not the tender parts of their embryo shoots exposed to injuries and depredations from the severities of the weather. Of this latter kind are the plants of the following list; some of them very large trees; others smaller woody vegetables, of the shrub and under-shrub kind: Citron, orange, lemon, calavva, mock orange, bad apple, shrubby swallow-wort, alaternus, shrubby geraniums, berry-bearing alder, Christ's thorn, Syrian mallow, boabab or Ethiopian four gourd, justicia, mild fena, the acacias and sensitive plant, coral tree, flinking bean trefoil, medicago, oleander, viburnum, fumach, ivy, tamarisk, heath, Barbados cherry, lavatera, rue, shrubby nightshades, Guinea henweed, cyprels, lignum vitae, and lavine, a species of juniper.
On annual plants, whose root as well as stalk perishes after a year, true buds are never produced; in their stead, however, are produced small branches, like a little feather, from the wings of the leaves, which wither without any farther expansion if the plants climb and have no lateral branches; but if, either by their own nature or from abundance of sap, the plants become branched, the ramuli just mentioned obtain an increase similar to that of the whole plant.
The same appearance obtains in the trees of warm countries, such as those enumerated in the above list, in which a plumula, or small feather, sends forth branches without a fleshy covering; as, in such countries, this tender part requires no defence or protection from cold. A fleshy covering then is peculiar to buds, as it protects the tender embryo enclosed from all external injuries. When we therefore speak of trees having buds that are naked or without scales, our meaning is the same as if we had said that they have no buds at all.
The buds that are to be unfolded the following year, break forth from the evolved buds of the present year, in such a manner as to put on the appearance of small eminences in the wings or angles of the leaves. These eminences or knots grow but little during the summer; as, in that season, the sap is expended on the increase of the parts of the plant: but in autumn, when the leaves begin to wither and fall off, the buds, placed on the wings, increase; and the embryo plant contained in the bud is so expanded, that the leaves and flowers, the parts to be evolved the following year, are distinctly visible. Thus in horse chestnut the leaves, and in cornel tree the flowers, are each to be observed in their respective buds.
As each bud contains the rudiments of a plant, and would, if separated from its parent vegetable, become every way similar to it; Linnaeus, to show the wonderful fertility of nature, has made a calculation, by which it appears, that, in a trunk scarcely exceeding a span in breadth, 10,000 buds (that is, herbs) may be produced. What an infinite number, then, of plants might be raised from a very large tree!