Plant family

“ X DECORATIVE PLANTS
There are few homes nowadays in which at least one plant of ornamental foliage cannot be found. I know of many in which some have had place so long that they have come to be considered as members of the family. Especially is this true among German people, who have an especial fondness for bride's myrtle and English ivy. In many of these homes I have found finer plants than I have seen in any greenhouse. I am not sure that they do not get more care than the children of the family. ”

“ This is the simplest family of real, undoubted plants; but there is one class still simpler, and that is the family of bacteria, about which you must have heard much, as many of them cause our diseases, though others do much valuable work for us. All the same, we will leave these little creatures alone, and content ourselves with the five great families of plants which we can see with our own eyes. ”

“ A large family having characteristic pealike flowers, a description of which has already been given in Chapter I. They all bear legumes, a pod that splits down one side, not both, as in Brassicaceæ. Besides the pea, the bean, vetch, alfalfa, lentil, locust tree, and dozens of valuable timber trees in the tropics belong here. Flowers all showy and absolutely dependent upon insects for fertilization. Seeds highly nutritious in many genera, and the roots of nearly all have bacteria associated with them. (See chapter on Food Habits of Plants.) ”

“ Not only are many species endowed with equal powers to obtain and keep possession of similar stations, but each plant, for reasons not fully explained by the physiologist, has the property of rendering the soil where it has grown less fitted for the support of other individuals of its own species, or even other species of the same family. Yet the same spot, so far from being impoverished, is improved, for plants of another family. ”

“ The families are quite close together, but are separate. Often members of different families are better friends than members of the same family, and that is still another way that plants are like people."
"Do you suppose the poison-ivy knows that it is poison?" asked Prue, who liked to believe that plants were really just like people.
"Perhaps it does. We can never be quite sure how much a plant knows. I told you once how I believed they could feel and hear, and [255] even see. I am almost sure that the dandelion can reason."
Davy looked interested, and the Chief Gardener went on. ”

“ When pollen from a plant of one family is placed on the stigma of a plant of a distinct family, it exerts no more influence than so much inorganic dust. From this absolute zero of fertility, the pollen of different species of the same genus applied to the stigma of some one species, yields a perfect gradation in the number of seeds produced, up to nearly complete or even quite complete fertility ”

“ These are further affected by the height and branching of the plant, and by the position of the seeds upon it. The disseminules of immobile species fall directly beneath the parent, and the resulting group is both uniform and definite. A similar arrangement is caused likewise by offshoots. An increase in mobility brings about a decrease of aggregation, since the disseminules are carried away from the parent plant. Perfectly mobile forms rarely produce family groups for this reason. ”

“ The water plants are very interesting in that the pollen is just light enough to float on the exact level of the mother part of the flower, otherwise fertilization could never take place, and there would be no more lovely lilies. Long throated blossoms are fertilized by their attraction for certain moths or humming birds who have long tongues. Mother Nature is exceedingly careful to reproduce her children, and in every conceivable way she sees to it that her plant-seeds are fertilized and distributed. ”

“ It is, in fact, not surprising that plants vary, but that the force of heredity will hold them into such recognizable categories that the red maple, or white ash, or blue cohosh are, with thousands of other species, after all fairly definite designations without which talking and writing about plants would be all but impossible. Some of our most beautiful garden plants have arisen either as the result of natural crossing, or crosses deliberately made by the plant breeder. ”

“ When a gardener wishes to obtain variations of a plant from which to select and establish a new breed, he deliberately sets to work to disturb—to shake up, to act upon in a tentative, experimental way—the germ-plasm of one or more parent plants by change of soil, climate, food and often by cross-fertilizing them with another breed or variety. ”

“ But suppose we are dealing with red clover where the flowers are small, almost sterile with their own pollen and produce only one seed. In this crop, the long and tedious method of continuous selection just mentioned must be used, for there is no other way. This method is often called the pedigree-culture method. The main idea of the plan is that the seeds of single plants are grown in isolated plots, and the character of the mother plant judged by the characters of the progeny. ”

“ But in spite of occasional exceptions this large group of polypetalous families do usually bear separate petals and sepals, and are among the most important of all the plant families. As they number over a hundred and contain thousands of species, all that can be done here is to mention a few typical or important ones. Just as in the apetalæ the families in this large group appear to show definite stages in development from simpler to more complex forms. But the steps are harder to trace and what appears simple characters in some plants are very complex in others. ”

“ At age seven or eight the foundation for sex-instruction should be laid by information concerning plant production; that the pollen dust of the father plant becomes attached to the legs of the honey-seeking bee and is transferred to the mother plant, where it fertilizes the seed from which a baby plant grows. The function of the wind, also, in effecting the conjunction of pollen with the ovule of the stigma should be explained; and how the pollen or male principle fertilizes and gives life to the female ovule, making seed from which a new plant is born. ”

“ The effort with the seedlings derived from each parent plant should be to find the plants that most closely resemble their own parents, and to manage these just as the parents were managed. No other should be allowed to flower. ”

“ Most blue blood was originally red of flaming hue, and when families begin to forget that fact, you can lay odds that the deep old roots of the family maple aren’t sending sap enough up to supply the high and mighty branches of to-day. When family trees get too high they wither at the top, and such dry sticks are only useful as fertilizer for younger trees. ”

“ Indeed, the faculty of spontaneous reproduction and perpetuation necessarily supposes a greater power of accommodation, within a certain range, than we find in most domesticated plants, for it would rarely happen that the seed of a wild plant would fall into ground as nearly similar, in composition and condition, to that where its parent grew, as the soils of different fields artificially prepared for growing a particular vegetable are to each other. ”

“ Equally efficient in the hands of the cultivator has been another method of producing new forms—namely, hybridization. If the pollen of a plant be transferred to the stigma of a related species, offspring is often produced; and the product is a batch of plants intermediate in characters between the two parents, and generally uniform in appearance. ”

“ Again, while the number of ovaries has been lessened, the number of seeds in each has been generally increased, which also marks a step in advance, since it allows many seeds to be impregnated by a single act of pollination. The result of all these improvements, carried further by some lilies than by others, is that the family has absolutely outstripped all others of the trinary class in the race for the possession of the earth, and has now occupied all the most favorable positions in every part of the world. ”

“ If the ground in old-established botanic gardens be dug much deeper than ordinary, it frequently happens that species which have been long lost are recovered, from their seeds being latent in the soil, as I have been assured by Mr. Fairbairn of Chelsea garden, and others.
The integuments of the seed, having fulfilled their destined office of protection, burst and decay. The young root is the first part of the infant plant that comes forth, and by an unerring law of Nature it is sent downwards, to seek out nourishment as well as to fix the plant to the ground. ”

“ But the different species of a genus, or genera of a family, usually have in common only a limited number of characters. A Rose does not seem to differ from a Rubus, or the Umbelliferæ from the Ranunculaceæ, in much else than the characters botanically assigned to those genera or those families. Unenumerated differences certainly do exist in some cases; there are families of plants which have peculiarities of chemical composition, or yield products having peculiar effects on the animal economy. ”

“ The balance of the reddish-purple plants, which comprise about two-thirds of the second generation, will, if their seeds are germinated, produce colored as against white-flowered progeny in the three-to-one ratio. In other words, these artificial crosses, made by the plant breeder, and this splitting up of hybrids which has been many times verified, are seen to be very fertile causes of the origin of new forms of plant life, if only the factor and character differences in the ancestry be sufficiently complex. ”

“ Plants must live together. They associate; they become adapted or accustomed to each other. Some can live in shade; they thrive in the forest, where sun-loving plants perish. Others prefer the sun, and thereby live together. There are plant societies.
Fig. 252. Weak, narrow-leaved grasses grow in the cat-tail forest.
Every distinct or separate area has its own plant society. There is one association for the hard-tramped dooryard,—knot-weed and broad-leaved plantain with interspersed grass and dandelions; one for the fence-row,—briars and choke-cherries and hiding weeds ”

“ It is, however, not clear why the simple transference into garden soil should result in such a thorough and persistent revolution in the plant organism. No one will seriously maintain that in the open country the development of plants is ruled by other laws than in the garden bed. ”

“ Reproduction and the ultimate scattering of fruits and seeds are absolutely necessary in order that colonies of plants may reach new localities. It is evident that plants best fitted to scatter their seeds, or place fruits containing the seeds some little distance from the parent plants, are the ones which will spread most rapidly. A plant, if it is to advance into new territory, must get its seeds there first. Plants which are best fitted to do this are the most widely distributed on the earth. ”

“ The same botanist remarks, that vegetable hybrids, when not strictly intermediate, more frequently approach the female than the male parent species; but they never exhibit characters foreign to both. A re-cross with one of the original stocks generally causes the mule plant to revert towards that stock; but this is not always the case, the offspring sometimes continuing to exhibit the character of a full hybrid. ”

“ These little leaves are thus comparable with seedlings, in that their polarity is not related to, or consequent upon that of the parent plant. They have in fact that "individuality," which we associate with germinal reproduction. ”

“ The Seed Plants, then, achieved their wonderful abundance and variety owing to the highly stimulating conditions offered by a terrestrial existence; we must assign to all the existing types a long terrestrial ancestry. How, then, about the water plants whose leaves and flowers so decorate our lakes? There seems no doubt [13] that they are species which have left the land to resume the aquatic habits of their remote ancestors. With few exceptions they retain the aerial mode of pollination which is the pride of the specialized land plants. ”

“ Each of these branches may do what every other branch does—produce leaves, flowers, fruits, seeds. It is not so with the higher animals, for in them each part may do something which some other part cannot do: if the part is a leg, it runs; if an ear, it hears. Each part serves the whole animal; and it cannot reproduce the animal. But in the plant, each branch lives for itself: it grows on the parent stock; or, if it is removed, it may grow in the soil. And if it grow in the soil, it is relieved of competition with other branches and grows bigger: it makes what we call a plant.
Fig. ”

“ The lower forms of plants multiply by subdivision, but in the higher plants they multiply by sexual conjugation, the different sex organs being produced in the same plant or in different plants. In these higher plants the conjugation is adventitious in that the pollen must be carried by the wind or by insects or other agencies from the male to the female plant. But the higher animals have the power of choosing their mates, so that the continuance in generations is controlled by volition. ”