Growth (botany)

“ The roots of air-plants, such as certain orchids, draw their nourishment from the air.
The experiment of marking roots and stem has been already tried, but it should be repeated. Repetition of experiments is always desirable, as it fixes his conclusions in the pupil's mind. The stem grows by a succession of similar parts, phytomera, each part, or phyton, consisting of node, internode, and leaf. Thus it follows that stems must bear leaves. The marked stems of seedlings show greater growth towards the top of the growing phyton. It is only young stems that elongate throughout. ”

“ The stem meanwhile is adding to its length throughout; it erects itself, and, seeking the light, brings the seed up out of the ground. The materials for this growth have been supplied by the cotyledons or seed-leaves, still in the seed: it was the store of nourishing material they held which gave them their thickish shape, so unlike that of ordinary leaves. Now, relieved of a part of this store of food, which has formed the growth by which they have been raised into the air and light, they appropriate the remainder to their own growth. In enlarging they open and throw off the seed-husk ”

“ The body c has lost its leaves through some accident, and its growth has ceased. In other words, the parts at aaaa are like the shoot fh, except that they are shorter, and they are of the same age. One grew from the end or terminal bud of the main branch, and the others from the side or lateral buds. Parts or bodies that bear leaves are, therefore, branches.—The buds at bbbb have no leaves, and they remain the same [119] size that they were a year ago. They are dormant. The only way for a mature bud to grow is by making leaves for itself, for a leaf will never stand below it again. ”

“ And when growth ceases above ground, and the leaves die and fall, or no longer act, then the roots generally stop growing, [Pg 35] and their soft and tender tips harden. From this period, therefore, until growth begins anew the next spring, is the best time for transplanting; especially for trees and shrubs.
73. The absorbing surface of young roots is much increased by the formation, near their tips, of Root-hairs (Fig. 81, 82) , which are delicate tubular outgrowths from the surface, through the delicate walls of which moisture is promptly imbibed. ”

“ A still more universal phenomenon than the vertical growth of stems and roots is the growth of plants generally, and it required as much or even more of the spirit of enquiry to propose the question, whether this growth can be explained by mechanical laws, and what that explanation is. ”

“ The word endogenous, inside-growing, is not, therefore, a correct one to describe the growth of most monocotyledons, for the growth takes place where the leaves originate, near the exterior of the stem. ”

“ But the whole plant, often many feet in length, consists only of single gigantic cells. A tough skin incloses its juices, which flow in a continuous stream through the stem, leaves, and roots of the curious growth, here taking up through the skin and assimilating mineral substances, there producing and transforming organic matter, and at the same time advancing the growth and increase of the whole. Not less peculiar than the inner structure and appearance of the stem is the form of the leaves of water plants. Their service to the organism is the same with that of the leaves of other plants. ”

“ Once it finds itself firmly rooted in the stem of its victim, it begins to grow vigorously. With every few inches of its growth it sends new roots deep into this stem. And when it feels quite at home, and perfectly sure of its board, it begins to wither away below, where it is joined to its earth root. Soon it breaks off entirely from this, and draws every bit of its nourishment from the plant or plants in which it is rooted. ”

“ The plant is thus provided with a mechanism for adapting its possibilities of growth to the supply of growth-promoting material which is available to it.
Many other plants produce far more buds than ever develop into growing tissues, and buds which, under normal conditions, remain dormant, under altered conditions start into growth and so provide for an "adaptation" of the total mass of the growing plant to correspond with the altered conditions of growth. ”

“ Why, when seeds are sown, and germination begins, does the leaf-germ seek the light, and the root-germ grow down into the earth?
Because the Creator has endowed every single seed with a [Pg 324] vital instinct which governs its development. The rootlet could more easily grow upward than downward, because of the looser earth, and of the exciting influences of light and moisture. Yet it takes the contrary course, leaving the leaf-germ to come up to meet the sun-light, and to send down to the stem and roots, the matter needed for their growth. ”

“ As the kernel swells with heat and moisture, its starches and albumens get oxidised and produce the motions and rearrangements of particles that result in the growth of a new plant. First a little head rises towards the sunlight and a little root pushes downward towards the moist soil beneath. The business of the root is to collect water for the circulating medium—the sap or blood of the plant—as well as a few mineral matters required for its stem and cells ”

“ We are not in the habit of treating dry seeds as though they were alive; beans are stored away in sacks all the winter and may be left for months in dry cellars, and the precious seeds which will give us our beautiful flowers in the summer are put away in boxes through the winter. Yet you know that if you place seeds in the earth and keep them warm and moist, little plants will come up and will grow. What gives them the power of growth which is not possessed by the stones and earth around them? ”

“ These changes, however, are not to be made in any ordinary plant, either by stimulating manures or any other kind of artificial culture; but can only be produced by observing a tendency to aberrations of growth in certain individuals of a genus, and carefully selecting the seed from those plants most inclined to exhibit such unusual or monstrous kind of growth. ”

“ The shapes of plants will depend on the character [161] of the seed, while the flower and fruit is dependent on the water and nutritive material. In all animals the first process of maturation and concoction of the nutritive liquids [162] takes place within the animal; there is no exception to this rule. But in plants the first concoction and maturation takes place in [163] the nutritive material. Every tree continues to grow up, until its growth is completed and it dies. ”

“ The production of a flower is preceded by an arrest of vegetation; this is obvious: the current of the plant's life becomes changed, the growth of the leaves is checked, the lengthening of the branches is arrested as the flower-bud forms; moreover, there is a close relationship in a large majority of flowers between the outer envelopes of the flower and the scales of a leaf-bud; this is especially so in regard to the venation, and is admitted by all morphologists. So far, then, it may be said that the production of a flower, like that of a bud, is due to a diminution of vegetative action ”

“ If you repeat this often with many plants you will find that these are the actively growing parts of the stems and roots; the individual leaves, of course, are also growing. Thus we see that growth is not a simple stretching of the whole, but that there are two definite regions where it is specially active. That of the stem and first root carry on the growth in opposite directions, as we noticed before (see p. 11) , the normal stem growing up into the air and the root down into the soil. ”

“ Corresponding to the invariable order of growth and progression in a plant as represented by the seed (enclosing the life and unifying principle) stem, branches, leaves and fruit, is the order of ascent, or perhaps it should be descent, by which Art takes concrete form. First there is the initial flow, then the root-point answering to the seed or unifying principle, then follow in turn, lines, planes, and solids. The fruit and the solids appear to be the culmination of the initial flow, but really they contain a potential power of growth in a realizable fluid motion. ”

“ When fairly established it makes rapid growth, and when in full leaf it proves very effective. Its propagation is easy with healthy plants; a length of the creeping root, with a crown to it, should be cut from the parent stock just before growth commences in early March. ”

“ This young lateral bud, which is frequently so small as to be unseen by the naked eye, is, in fact, the vitalized, undeveloped stem that is to increase in size if growth takes place. The writer is of the belief that in this growing-point the individuality of higher plants should be located. If there are two buds upon the phyton, it seems proper to say there are two individuals, as there are two distinct points of growth, and two branches may result therefrom. ”

“ Several causes operate to increase the yield when large seed [104] pieces are planted. The larger the cutting the greater generally the number of eyes and the number of stalks. The young shoot, before it develops a strong system of feeding roots, is dependent for nutriment on the material stored up in the seed piece; hence the more abundant this supply the more vigorous the growth of the plant and this increased luxuriance is not confined to the early stages of growth, but is marked throughout the growing season. ”

“ When, however, plants are expenders, namely, during their germination and first stages of growth, their degrees of growth are determined by their amounts of vital capital. It is because the young tree commences life with a ready-formed embryo and store of food sufficient to last for some time, that it is enabled to strike root and lift its head above the surrounding herbage. ”

“ Naturally, too, we need not expect them in plants having modes of growth which early produce an outer practically dead part, that effectually shields the inner actively living part of the stem from the influence of the medium—long-lived acrogens such as tree-ferns and long-lived endogens such as palms. ”

“ Just as that small portion of nourishing matter which is deposited in the seed feeds the embryo when it germinates, so the much larger portion deposited in the tuber nourishes its buds, or eyes, when they likewise grow, the next spring, into new plants. And the great supply enables them to shoot with a greater vigor at the beginning, and to produce a greater amount of vegetation than the seedling plant could do in the same space of time ”

“ Thorough cultivation serves to retain moisture, increases the activity of the bacteria which convert the plant food into available form, prevents weeds, and promotes heavy root development which in turn increases the growth and productiveness of the plants. ”

“ The arum, like the grain of wheat, has only a single seed-leaf; whereas the pea, as we all know, has two. This is the most fundamental difference among flowering plants, as it points back to an early and deep-seated mode of growth, about which they must have split off from one another millions of years ago. All the one-lobed plants grow with stems like grasses or bamboos, formed by single leaves enclosing another; all the double-lobed plants grow with stems like an oak, formed of concentric layers from within outward. ”

“ Plants cannot use the “plant-food soup,” just as it is taken up by the roots, to make new growth.
The leaves must first turn the liquid food into starch, which is the right kind of food for the plant.
A leaf has been called a leaf-mill, because it has many tiny grinding stones.
These tiny grinding stones are the green grains in the cells which form the leaf. They are called chlor-o-phyll bodies.
The leaf-mill grinding stones are turned by sunshine power. Without sunshine they cannot work. ”

“ As soon as the third leaf is developed, go over the piece, and boldly thin out the plants. Wherever they are very thick, pull a mass of them with the fingers and thumb, being careful to fill up the hole made with fine earth. After the fourth leaf is developed, go over the piece again and thin still more; you need specially to guard against a slender, [Pg 17] weak growth, which will happen when the plants are too crowded. ”

“ Every tree, sooner or later, reaches a point which we call its period of maturity, when some of its buds are thus modified. The same elemental parts are still present; but those that were arranged for the production of an elongated shoot, with leaves set around it in some definite manner, and destined for the formation of woody growth, are now so constituted as to have a growth of very short extension, and furnished with modified leaves, so changed, that we scarcely recognize them thus crowded together upon this shortened and modified axis. ”

“ In planting, a little extra care in the disposition of the roots in the soil will be well repaid, for plants merely thrust into the ground cannot develop that robust root growth on which the future of the crop largely depends. ”

“ When these plants are full two feet high, the top of the stems are broken off, to make the leaves grow thicker and broader. Here and there are left a few plants without having their tops broken off, in order that they may afford seeds for another year. Throughout the summer the other plants are from time to time, pruned at the top, and the whole field is carefully weeded to make the growth of the leaf so much the more vigorous. ”

“ The foliage dies down during the winter, but the root sends up a new, strong growth, which, I fear, will burn in the South and on light soils. Staminate.
Prouty's Seedling.—Plant not very vigorous; leaf-stalk very smooth; truss 3 to 5 inches; berry bright scarlet, glossy, very long conical; flesh pink, firm; flavor fair; calyx close. Very productive, but the plant does not seem vigorous enough to mature the enormous quantity of fruit that forms. With high culture on heavy soil, I think it might be made very profitable. Staminate. ”