In the first century BC another scholar, Pedanio Dioscorides, a Greek physician and pharmacist from the time of Nero, published the first "herbarium": De Materia Medica, a sort of pharmacological encyclopedia composed of five books, in which he described over 500 plants, specifying their aromatic or medicinal properties. This treatise, widespread in the Greek world, was instead ignored by the Latins because of the Naturalis Historia, the work of the famous Pliny the Elder: it was an encyclopedia in thirty-seven books that gathered all the knowledge that had come up to that time on scientific and technical subjects, including botany.
The treatises of Theophrastus and Dioscorides represented all the knowledge related to botany until the sixteenth century, when the advent of the microscope facilitated scientific observations and the invention of printing allowed a greater dissemination of knowledge. Already in the Middle Ages there were the Horti Sanitatis, located near monasteries and pharmacy schools, where medicinal plants were cultivated for educational and therapeutic purposes; the most famous in Italy was the Giardino della Minerva, founded in 1300 in Salerno for the students of the Salerno medical school.
The new discoveries favored the spread of the Botanical Gardens, natural environments designed to artificially recreate the typical living conditions of certain species of plants, for educational and in-depth purposes; the first Botanical Gardens were born in Italy, in Pisa (in 1543), in Padua and Florence (in 1545), in Bologna (in 1567). Naturalistic observation extended not only to native species but also to tropical flora. Botanical Gardens were also founded in the rest of Europe: in Leiden in the Netherlands, next to the University, in 1590 a Garden was established in which different tropical species were cultivated. The same tulips, symbolic flowers of Holland, have oriental origins (to be exact, Turkish): they were imported to Holland in the 16th century by the famous botanist Carolus Clusius, prefect in charge of managing the garden itself, thanks to his contacts with the Company Dutch of the East Indies. Other botanical gardens were founded at the same time at Oxford in England, at Montpellier in France, at Leipzig and Heidelberg in Germany.
Starting in the mid-twentieth century, thanks to the optical microscope, scientific discoveries in the field of botany underwent a new turn: the plant organism is in fact simpler to study and understand than the animal, and its observation has made it possible to draw important conclusions for example on the inheritance of characters, on the production of antibiotic substances, on the analysis of growth.
As mentioned, botany deals with the study of vegetables: to precisely circumscribe this category, it is necessary to observe some characteristic aspects of the living being: its nutrition mechanism, usually autotrophic, the typically sessile (stemless) form, the presence of roots, lack of nerve organs. According to this classification, the following are included in the plant kingdom: Algae (distinguished between blue algae and real algae), Mushrooms (distinguished between true fungi and molds), Bryophytes (eg mosses), Pteridophytes (eg ferns), Spermatophytes (distinguished between Conifers and Angiosperms or flowering plants). Then there are the Bacteria, considered an atypical element of the vegetable kingdom.
The vegetables are in general autotrophic organisms, that is able to feed themselves using the spontaneously available elements in the water, in the air and in the ground: from the soil they absorb inorganic substances necessary for their nourishment, they dissolve them through water, and thanks to the sunlight performs chlorophyll photosynthesis, transforming carbon dioxide and water into oxygen and sugars. This is undoubtedly true for green plants, while for example mushrooms are heterotrophic: they are not able to synthesize the primary elements available in nature to transform them into the nourishment they need, but they must find it already ready. To do this, they interact with other organisms in a saprophytic manner (they feed on decaying dead organisms, helping to clean up the environment), or parasite (attack living organisms in difficulty, eg diseased plants, accelerating their death) or finally symbiotic ( they exchange nutrients with other vegetables, without damaging each other).
In the past Botany was divided into two macro-categories: the General Botany, dedicated to the study of plant structures and physiological processes, and the Special Botany (or Systematics) dedicated to the study of plant groups; the latter was in turn distinguished in Botanica Fanerogamica, for plants with flower production, and Crittogamica which instead concentrated on algae, fungi and lichens. A more recent classification instead provides for the distinction, among others, in Morphological, Physiological, Systematic, Ecological Botany, where each of these addresses focuses on a specific area of observation.
Sistematica botany deals with the naming and classification of plants within a system: it groups plants by variety, species, genus, order and class based on their similarities. The nomenclature system currently in use is based on the principles established in the eighteenth century by Carlo Linneo, and collected in the International Code of Botanical Nomenclature, which is periodically examined and updated. Morphological botany observes the external and internal attributes of plants, and then classify them into homogeneous groups; from these analyzes we also derive the study of reproductive phenomena, which presents areas of overlap with the cytological botany, which studies the cellular structures of the plant in greater depth, starting from the behavior of the cell nucleus and its chromosomes during reproduction.
To quote a few more branches among the most famous, there is Genetics, based on the studies carried out by the Augustinian friar Gregor Mendel, who through the observation of cultivated peas formulated the first laws on the inheritance of characters. Geobotany analyzes the geographical distribution of different types of plants; Paleobotany explores the history of flora starting from the study of fossil plants. The study of agricultural plants is treated in the Agronomy or Agricultural Botany, while medicinal plants are studied in Pharmacological Botany.