 Botany, botany, also called plant science s, plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specializes in this field. Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of embarrassed of the International Botanical Congress. Nowadays, botanists in the strict-sensed study approximately 410,000 species of plant plants of which some 391,000 species are vascular plants including ca. 369,000 species of flowering plants and ca. 20,000 are brightophytes. Botany originated in prehistory as hergillism with the efforts of early humans to identify, and later cultivate, edible, medicinal and poisonous plants, making it one of the oldest branches of science. Medieval physics gardens, often attached to monasteries, contained plants of medical importance. They were for runners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Paldo Botanical Garden. These gardens facilitated the academic study of plants. Efforts to catalog and describe their collections were the beginnings of plant taxonomy, and led in 1753 to the binomial system of carolinias that remains in use to this day. In the 19th and 20th centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. In the last two decades of the 20th century, botanics exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other arias of science and technology. Research topics include the study of plant structure, growth and differentiation, reproduction, neurochemistry and primary metabolism, chemical products, development, diseases, evolutionary relationships, systematics, and plant taxonomy. Dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues. Botanical research has diverse applications in providing staple foods, materials such as timber, oil, rubber, fiber and drugs. In modern horticulture, agriculture and forestry, plant propagation, breeding and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, and environmental management, and the maintenance of biodiversity.