Botany

Botany (from the Greek: βοτάνη [botane] = plant), also called plant science(s), plant biology or phytology, is the discipline of biology that studies the forms of life in the plant world (flora), especially in relation to their anatomy, physiology, utility, classification, and ecology. The most complex organisms studied by botany constitute the kingdom of plants (or Plantae).

In the past, everything that was not considered animal was considered a plant, vegetable. Currently, only autotrophic multicellular organisms are considered part of the Plant Kingdom: the others are assigned to the kingdoms Monera, Protist, or Fungi.

Botany is divided into several branches. The first subdivision is that which distinguishes a general botany and a special botany: the first deals with the general characters of plants, abstracting in a sense from the specific entities; it describes their structure as to organs and external form (morphological botany or plant morphology), through its more specialized branches such as cytology, histology, anatomy, embryology and genetics; it tries to explain the various vital phenomena that occur during their development and that preside over them (physiological botany or plant physiology); it is interested in the relationships between the various plants and of these with the environment (ecological botany or plant ecology); it studies the alterations of form and their causes (pathological botany or plant pathology), although in this case it also extends its interests to special botany.

The latter, which is the analytical study of individual plant organisms, names them and fixes their distinctive characters, then bringing them together according to specific affinities, generic and so on, that is, according to taxonomic entities of various levels (systematic botany or taxonomy), as many parts of systematics that most often rise to real autonomous disciplines (microbiology, algology, mycology, bryology, etc.). But botany, as the study of plants, cannot ignore their possible use, so we have applied sciences such as agricultural botany, horticultural, medical, pharmaceutical, commercial, industrial.

In addition, the study of plants must not stop at current organisms as a phenomenon in itself, but also look at the types of the past (paleontological botany or paleobotany). Botanical geography or geobotany or phytogeography, on the other hand, studies the relationships between plants and the globe in terms of distribution and diffusion on it, taking into account the dynamic aspect as well as the ecological and structural characteristics of the various plant complexes, in some cases even specializing in detailed research of plant communities (phytosociology).

Historical notes

The interest for plants useful to mankind is proven by archaeological researches and historical documents among the most ancient people. In the writings of the first Greek philosophers of nature there is no clear distinction between plants and animals. The same Aristotle thought that plants were derived from animals with many legs in which the head was transformed into a root and in which it had lost all sensory and motor capacity: the plants remained only the vegetative soul.

To Theophrastus (4th-3rd century BC), a student of Aristotle, dates back the first scientific work in the field of botany where are analyzed the organs responsible for nutrition and reproduction (roots and seeds) and appears the first classification of plants into trees, shrubs and herbs. The ways of life of plants and their cultural needs are also treated by many Roman writers such as M. Terenzio Varrone, Columella and Plinio il Vecchio. To the first century BC dates back the work of the Greek Dioscorides in which are described about 600 plants especially of medical interest.

In the Middle Ages little added to these treatises Arab writers or observations, albeit original, of Albertus Magnus. The beginning of the sec. XVI marked a reawakening for the study of botany, with the printing of works called herbari where are described, even with the help of engravings, plants not always known to the ancients, as well as those of the New World. They are encyclopedic works in which are listed for each plant names, form, judgments of the ancients, therapeutic virtues, habits, etc.. Among the best known authors are O. Braunfels and L. Fuchs in Germany, M. de L’Obel in England, P. Mattioli in Italy (here arose towards the middle of the century and spread throughout Europe the first botanical gardens, initially linked to the faculties of medicine).

A new scientific commitment is found in the work of A. Cesalpino, who, inspired by Aristotle, compares organs and functions of animals with those of plants. For Cesalpino, the pith of plants corresponds to the intestine of animals and from it comes the seed. The outer shell of the seed comes from the wood and the fruit from the bark. The flower is just a protective organ of the seed and in plants there is no distinction between sexes. Based on the characters of fruits and seeds, Cesalpino proposed an arrangement of plants by introducing an artificial classification system which was opposed by subsequent attempts of natural classification, based on the similarity of all important organs of the plant.

In the seventeenth century C. Bauhin, who described about 6000 plants adopting the binomial designation of genus and species; J. Jung, who based on the analysis of inflorescences identified some important classes (Compositae, Labiatae and Leguminosae); and finally J. Ray, who considered the leaves as important for the classification as flowers and fruits. In the second half of the XVII century, microscopic researches illustrated the fine anatomy of plants, especially by N. Grew and M. Malpighi, who also specified the embryonic development. By means of anatomical and experimental investigations, R. Camerarius, at the end of the century, identified the sexuality of plants, a subject that was later addressed by J. G. Kölreuter and C. Sprengel. Sprengel.

The distinction of male (pollen) and female (ovaries) elements in plants and the interest in generation tended to privilege the reproductive organs as a criterion of classification. Important was the one proposed by J.P. Tournefort on the basis of the diversity of the corolla of the flowers and which was supplanted towards the half of the XVIII century only by the more elaborate one of Linnaeus. The great Swedish botanist distinguished 24 classes according to the number of stamens and these were subdivided in orders according to the number of pistils.

The adoption of binomial nomenclature and the precision of his descriptions thus imposed his classification program as a scientific ideal on several generations of naturalists. For many of his contemporary researchers, this knowledge had to retrace the natural scale that extended continuously from minerals to man, according to the divine design of creation. Also in the eighteenth century began important research in plant physiology, from the experiments of S. Hales on the movement of the sap and transpiration, to those of J. Priestley which showed that plants produce oxygen.

After the chemical and physiological investigations of Lavoisier, J. Ingenhousz could specify that the absorption of carbon dioxide is a process of nutrition for plants. Animal world and plant world appeared so linked by a relationship of mutual dependence that in the first half of the next century biochemical research of J. Senebier, T. de Saussure and J. Liebig specified better for other substances. The idea of the circulation of life was proclaimed, so that plants recompose the residual substances of animals, reconstituting for them always new nourishment.

As in zoology, so also in botany in this period they tried to find, through the study of comparative anatomy or morphology, the criteria for a new natural classification. Among the many authors the main ones were A. L. de Jussieu and especially A. P. de Candolle, who set himself the task of ordering about 100,000 plants. Many of these, and precisely the Cryptogams, however, escaped the traditional criteria of classification and could be studied only with the new microscopic techniques perfected in the nineteenth century. It is to these techniques that we owe, also by the work of M. J. Schleiden, the rise of the new cellular theory that united botany and zoology in a single biological science. To this contributed even more the theory of evolution imposed by the work of Darwin and on the basis of which it was finally possible to set the program of a natural classification of all plant forms on the basis of common descent (A. Engler, K. Goebel, K. Prantl).

In the second half of the nineteenth century, the microscopic study of cell structure, especially the behavior of chromosomes of the nucleus by both zoologists and botanists (H. Mohl, E. Straburger), as well as research in the field of evolution (C. Nägeli, H. de Vries), opened the way to the great unitary field of research of biology of the twentieth century, genetics, whose principles had already been formulated around 1860 by G. Mendel. Despite the continuous and necessary multiplication of specializations and research directions in botany, genetics, as well as molecular biology, shows more and more clearly the existence of elementary processes common to animals and plants and the importance of an interdisciplinary study in the research on living organisms.

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