Botany is a natural science concerned with the study of plants.
The main branches of botany (also referred to as "plant science") are commonly divided into three groups: core topics, concerned with the study of the fundamental natural phenomena and processes of plant life, the classification and description of plant diversity; applied topics which study the ways in which plants may be used for economic benefit in horticulture, agriculture and forestry; and organismic topics which focus on plant groups such as algae, mosses or flowering plants.
groups of organisms - clades, grades and guilds study of chronological dating using plants