Botany, also called plant science or plant biology, is the science of plant life and a branch of biology. A botanist is a scientist who specializes in this field of study. The term "botany" comes from the Ancient Greek word βοτάνη (botane) meaning "pasture", "grass", or "fodder". A person who studies plants may be called a botanist or a plant scientist. Traditionally, botany has included the study of fungi and algae, studied by mycologists, phycologists respectively, with the study of plants and these three groups of organisms remain within the sphere of interest of the International Botanical Congress. Nowadays, botanists study approximately 400,000 species of living organisms of which some 260,000 species are vascular plants and about 248,000 are flowering plants.
Botany originated in prehistory as herbalism 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 physic gardens, often attached to monasteries, contained plants of medical importance. They were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Padua botanical garden. These gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings ofplant taxonomy, and led in 1753 to the binomial system of Carl Linnaeus 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, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately.
Plant ecology is the science of the functional relationships between plants and their habitats the environments where they complete their life cycles. Plant ecologists study the composition of local and regional floras, their biodiversity, genetic diversity and fitness, theadaptation of plants to their environment, and their competitive or mutualistic interactions with other species.The goals of plant ecology are to understand the causes of their distribution patterns, productivity, environmental impact, evolution, and responses to environmental change.
Plants depend on certain edaphic (soil) and climatic factors in their environment but can modify these factors too. For example, they can change their environment's albedo, increase runoff interception, stabilize mineral soils and develop their organic content, and affect local temperature. Plants compete with other organisms in their ecosystem for resources.They interact with their neighbours at a variety of spatial scales in groups, populations and communities that collectively constitute vegetation. Regions with characteristicvegetation types and dominant plants as well as similar abiotic and biotic factors, climate, and geography make up biomes like tundra ortropical rainforest.