Plant propagation

“ Active motion, local and general, though usually of relatively small amount, accompanies all plant-growth. Throughout root, stem, leaf, and flower transference of material is going forward vigorously. The root hairs and stomata are working at high pressure; the chlorophyll never ceases its activities while daylight lasts. Externally, the growing branches, leaves, and flowers also display incessant movement, sweeping the air in small circles, or in the case of climbing plants in curves of considerable amplitude. ”

“ In the first place, the enormous holdfast, ensured by the millions of points of adherence, enables the plant to withstand even powerful lever actions from above, and provides fixed points against which the root-tips can work as they drive deeper into the soil. In the second place, the intimate contact of the root-hairs and particles of soil, ensures that the films of water held by surface-action on the soil-particles and root-hairs shall be in continuity with the water saturating the cell-walls of the latter, and therefore with the protoplasm and cell-sap in their interior. ”

“ The moment, however, that the roots of one enter the area from which the other draws its water supply, or the foliage of one begins to overshade the leaves of the other, the reaction of the former modifies unfavorably the factors controlling the latter, and competition is at once initiated. The same relation exists throughout the process; the stronger, taller, the more branched, or the better rooted plant reacts upon the habitat, and the latter immediately exerts an unfavorable effect upon the weaker, shorter, less branched, or more poorly rooted plant. ”

“ The vegetation form of the invading species is often of the greatest importance in determining whether it will become established. The vegetation form represents those modifications which, produced in the original home by competition, i. e., the struggle for existence, are primarily of value in securing and maintaining a foothold. These comprise all structures by means of which the plant occupies a definite space in the air, through which the necessary light and heat reach it, and in the soil, from which it draws its food supply. ”

“ They never grow into branches, but detach themselves when full grown, fall to the ground, and take root there to form new plants.
Fig. 110. Bulblets in the axils of leaves of a Tiger Lily.
117. Consolidated Vegetation. An ordinary herb, shrub, or tree is evidently constructed on the plan developing an extensive surface. In fleshy rootstocks, tubers, corms, and bulbs, the more enduring portion of the plant is concentrated, and reduced for the time of struggle (as against drought, heat, or cold) to a small amount of exposed surface, and this mostly sheltered in the soil. ”

“ Should the soil of fields or greenhouses be much colder than the air, the plant suffers. When in a warm atmosphere, or in a dry atmosphere, plants need to absorb much water from the soil, and the roots must be warm if the root-hairs are to supply the water as rapidly as it is needed. If the roots are chilled, the plant may wilt or die. ”

“ If you go along the lanes and in the gardens in the height of summer when it is hot and dry and the sun beats on the plants all day, you may see them beginning to wither for want of water. The roots are not able to find enough moisture in the soil to supply the leaves, which, being in the hot air, continue to transpire away the water resources of the plant, so that in the end each of its cells must suffer and the whole become limp and droop. ”

“ At the end of its life, and in consequence of drought, its texture becomes almost woody, its branches curve up into a sort of ball, the valves of its pods are closed, and the plant holds to the soil by nothing but a root without fibers. ”

“ The heat of the sun’s rays, which is intended by nature to warm the soil, will be expended in evaporating the water from its surface; and thus the plants will never receive that genial warmth about their roots which so much favours their rapid growth. Where too much water is present in the soil also, that food of the plant which the soil supplies is so much diluted, that either a much greater quantity of fluid must be taken in by the roots,—much more work done,—or the plant will be scantily nourished. ”

“ A small portion of air to be admitted on fine days, to purify the atmosphere of the house. Keep the surface of the soil in the pots free from weeds, as also from moss and lichen; but when doing so do not loosen the soil so as to injure the roots near the surface. Keep every plant free from dead leaves, and all climbing plants neatly tied up. The Achimenes, Clerodendrons, Erythrinas, Gloxinias, and the various bulbs will now be approaching a state of repose, and therefore will require but little or no water. ”

“ If we have a tree growing on a hillside in a soil that easily transmits moisture and it gives that tree constantly a stream of pure water going through its root system, and there happens to be enough fertility in that vicinity, that moisture is impregnated with plant food, and the tree will get all it wants. ”

“ The denuding effect of wave or current action is countered by the network of creeping stems and abundant roots which the plants possess, forming a tough felt which floats, and by its growth and decay helps materially to form fresh land. Another effect of the creeping and branching stem-systems is the production of extensive and dense groves of many of the species.
When we pass beyond the reed zone, a completely different type of vegetation prevails. Here the plants are essentially aquatic. They make no effort to raise their stems and leaves above the water surface ”

“ Those plants which are left in the ground during the whole year should have their roots opened immediately on the close of the rains, the superabundant or decayed tubers, and all suckers being removed, and fresh earth filled in. The earth should always be heaped up high around the stems, and it is a good plan to surround each plant with a small trench to be filled daily with water so as to keep the stem and leaves dry. ”

“ Judging from the general laws of the distribution of plants, and from the analogy furnished by Viola calaminaria, we may expect that an indicative plant will be, not a distinct species, but a variety of some widely distributed species, the range of the species as a whole being determined by general conditions of climate, altitude and soil, while the characteristics of the variety are affected by causes peculiar to the mineral deposit. Temperature and moisture, as Agricola long ago pointed out, are among these causes, and color is one of the most sensitive of their effects. ”

“ Having last month put the house in complete order, all that remains necessary to be attended to, is the state of the plants and pots, which should be regularly examined, and of those where the roots fill the soil, a little may be taken off the top, supplying its place with fresh earth, thereby giving what is called a top dressing. Give each a sufficient rod that requires it, tieing the plant neatly thereto; minutely scrutinise each for insects, and where they are detected, have them eradicated. ”

“ In the last case, if the plants used are from the same formation, the results will have almost the value of a field determination. When no definite habitat is the subject of investigation, an actual soil, and not an artificial mixture, should be used, and the plants employed should be mesophytes. The individual plants are grown from seeds in the proper soils, and are repotted sufficiently often to keep the roots away from the surface. The last transfer is made to a pot large enough to permit the plant to become full-grown without crowding the roots. ”

“ Since the effective operations of the currents are limited to the shore-plants with buoyant seeds or fruits, such plants forming but a small proportion of any flora, it must be acknowledged that, numerically speaking, the results of the dispersing-agency of the currents on plant-distribution in general are but slight. ”

“ We have now glanced at the most distinctive of the plant formations which we meet with in our own country, and find that they accompany extreme conditions relating to water and soil: it remains to return to the consideration of the vegetation which develops under conditions of a more normal character—on ordinary soils, in fact, which are neither very wet nor very dry. ”

“ As a rule, it is not desirable to have either seeds or seedling plants in the ground for any length of time when the temperature is too low for active vegetation; for while they rest, other, lower organisms (fungi and bacteria) , adapted to low temperatures, may continue in full activity at the expense of the vitality of the crop plant. ”

“ This is the first process, and, properly speaking, is all that belongs to the springing or elongation of trees; and in many plants, that is, all those which are annual or deciduous, there is no other process; the plant absorbs juices from the earth, and in proportion to the quantity of these juices increases in size: it expands its blossoms, perfects its fruit, and when the ground is incapable by drought or frost of yielding any more moisture, or when the vessels of the plant are not able to draw it up, the plant perishes. ”

“ Here we have a case in which burnt soil and ashes favour the germination of a particular plant, whose seeds are easily carried by the wind, and it is not difficult to see how this peculiarity might favour the dispersal of the species for enormous distances, by enabling it temporarily to grow and produce seeds on burnt spots. ”

“ This will cause the water-plants to die sooner or later, and land-plants will replace them.
There is continual change in the arrangement of lakes and rivers, hills and shores, which takes place all around us, but so slowly that we do not notice it. It is slow, and therefore there is not a sudden killing off of any one kind of plant, and a rapid incoming of a different set of plants, but it causes a gradual shifting and moving of the groups among themselves. ”

“ 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 ”

“ Let them alone, except to weed, until the plants are from twelve to fifteen inches high—at which time they are to be earthed up.
Earthing Up.—In dry weather, with a short, hand-hoe, draw in the earth gently from each side and bring it up carefully to the stalk. The soil must be kept out of the plant, and it is best for the first and perhaps the second time of earthing, to gather up the leaves in the left hand, and holding them together, to draw the earth about them. Fill in about once in two weeks, and always when the plants are dry. ”

“ The growth of a plant is in its ultimate analysis a group of motions put forth in adjustment to a group of physical and chemical conditions in the soil and atmosphere. A fine illustration is the spiral distribution of leaves about the stem, at different angular intervals in different kinds of plants, but always so arranged as to ensure the most complete exposure of the chlorophyll to the sunbeams. Every feature of the plant is explicable on similar principles. It is the result of a continuous adjustment of relations within the plant to relations existing outside of it. ”

“ You know that they are stowing away their food in warmer, safer places than can be supplied by the delicate leaves. And when all the food has been drawn out of the leaves, and packed away in the right spots, then the plant finishes a piece of work it began some time before. This piece of work is the building-up of a row of little cells just where the leafstalk joins the stem or branch. When this row is complete, it acts almost like a knife, loosening the stalk from the stem. ”

“ Those living surfaces of the plant which are most exposed to light are green or highly coloured. The root tends to grow downward, but the stem tends to grow upward toward light [16] and air. The plant is anchored or fixed in the soil by the roots. Plants have been called “earth parasites.”
The Foliage Part.—The leaves precede the flowers in point of time or life of the plant. The flowers always precede the fruits and seeds. Many plants die when the seeds have matured. The whole mass of leaves of any plant or any branch is known as its foliage. ”

“ Any part of the stem may produce them, but they most readily come from the nodes. As a general rule they naturally spring, or may be made to spring, from almost any young stem, when placed in favorable circumstances,—that is, when placed in the soil, or otherwise supplied with moisture and screened from the light. For the special tendency of the root is to avoid the light, seek moisture, and therefore to bury itself in the soil. Propagation by division, which is so common and so very important in cultivation, depends upon the proclivity of stems to strike root. ”

“ In this range of the germinating process we may possess an epitome of the history of the climatic conditions of plant-life from an early era in the world’s story, beginning with those ages when perhaps under the uniform conditions that then prevailed, all plants were more or less coast-plants and more or less viviparous, and coming down to the present era when with an extensive and varied land-surface there is great variety both in climate and in the range of germination. ”