An incipient or nascent shoot; the rudimentary or beginning state of a stem; particularly, in common speech, a thickened and condensed resting-stage of a shoot, or a flower or leaf before expanding; in propagating, a single bud used on a cutting or cion.
Standard Cyclopedia of Horticulture
BudsCH. A bud is an incipient shoot or short growth- axis concealed by the closely investing leaves, or leaf- parts, that it bears. The foliage-shoots and flower-shoots of all seed plants arise from buds. The leaves converge over the true stem-apex or growing-point. The essential thing is that this growing-point continues the terminal growth and gives rise laterally, behind the point, to new leaves, in the axils of which buds may be formed ultimately. In the plumule of the seed the first bud activity is manifest, and thenceforth a bud marks every growing stem-apex.
Normally the leaves arise back of the stem-apex, first as small protuberances, which soon flatten laterally. They grow faster than the stem-apex, and by more rapid growth on the under surface they bend over, forming for the time a part of the bud or bud-cluster of leaves which effectively protects the delicate tip. In many herbaceous plants the shoot elongates throughout the growing period, so that each leaf or whorl of leaves in turn has a more or less equal work as a part of the bud. As the apex elongates and each leaf develops, greater growth on the inner (upper) surface effects its complete exfoliation. Using favorable material, one may completely dissect the bud, laying bare the growing- point, which may be readily examined with a hand- lens. Either of the little pondweeds commonly cultivated, Elodea or Hippuris, may be used for this purpose. The buds which are commonly most conspicuous and at the same time most highly specialized are the "resting" buds of temperate shrubs and trees. Such buds are often scaly buds, and they are characteristic of all climates in which there is an interruption to growth, either through cold or dryness. In this case the stem- apex and younger leaves are normally inclosed by persistent more or less indurated leaf-parts modified as bud-scales. Resinous secretions may accompany the scales and the younger leaves may be covered with hairs. The size, form and minute characters of such buds vary widely, but obviously they are, in general, wondrously efficient in the resistance exhibited towards rigorous climatic conditions. The important point is that the bud- structures quite effectually prevent drying out of the young shoot which is there tucked away.
Particularly interesting is the fact that the resting-bud of many trees includes in miniature the entire vegetative or flowering shoot of the next season. In such case the rapid elongation of the axis and unfoldingof leaves in the spring is soon followed by the formation of a new resting-bud wherein the shoot of another year is gradually differentiated. Every gradation occurs between this type and the fruit-buds on the left, typical active bud of annuals.
Interest in buds centers in their spring activity, properly in the awakening and growth resulting when the conditions have remained favorable sufficiently long. Leaves and axes enlarge and elongate rapidly, bursting asunder the dead scales and often carrying forward the expanding younger ones. The growth of the younger scales exhibits the true nature of these strictures, some of which are found to be leaf petioles, some petioles with minute blades; and various other modifications occur. Many resting- buds are awakened from their comparative inactivity by a few days of favorable weather. These are "early" flowers, and of this type are the lilac and the golden bell. Other buds require a longer period, such as the oak and the hickory. It is not strange, therefore, that some plants lend themselves readily to early forcing by etherization, the hot water treatment, and the like, while others are with great difficulty forced.
In the preceding, more specific mention has been made of buds which develop leafy shoots, that is of leaf-buds. It is clear, however, that the resting-bud, as well as an herbaceous bud, may develop a single flower, as in the peach; a cluster of flowers, as in the red maple; or a shoot with leaves and flowers, as in the apple and Norway maple. The occurrence of leaf- and flower-buds with respect to the age of the twig and the relation of pruning to bud disposition are questions of special horticultural interest, but cannot receive consideration in this brief account.
Buds are normally produced terminally and in the axes of leaves, the latter arrangement therefore corresponding to leaves; but under exceptional circumstances they may arise from the growing tissue of any member. Buds from the roots of the sweet potato and dahlia are important in propagation; likewise are those produced by the leaves of certain species of Begonia. As a matter of fact, buds originating from internodes, roots and leaves—so-called regenerative-buds—are not uncommon; but the development in such situations occurs as a rule only when normal buds are not present.
Buds with the leaves and leaf-parts surrounding them are sometimes organs of food-accumulation. The typical bulb is little more than a fleshy bud, and there are all gradations between the typical bulb and the typical tuber-^the latter with many buds.. Small bulb-like buds occur in Liliurn bultriferum and a few other plants, and they are always important in propagation. It requires no stretch of the imagination to classify the edible shoots of brussels sprouts among unusual buds; and from this it is no great leap to the monstrous "bud" of the cabbage.
|This article contains a definition from the Glossary of Gardening Terms.|